diff --git a/chore/gentests/gentests.go b/chore/gentests/gentests.go
index 2a8c2214..2eb83129 100644
--- a/chore/gentests/gentests.go
+++ b/chore/gentests/gentests.go
@@ -33,6 +33,7 @@ func main() {
 
 	llgenDir(dir + "/cl/_testlibc")
 	llgenDir(dir + "/cl/_testrt")
+	llgenDir(dir + "/cl/_testgo")
 	llgenDir(dir+"/cl/_testpy", "")
 	llgenDir(dir+"/cl/_testdata", "")
 }
diff --git a/cl/_testdata/print/out.ll b/cl/_testdata/print/out.ll
index 0e4003b5..27462d72 100644
--- a/cl/_testdata/print/out.ll
+++ b/cl/_testdata/print/out.ll
@@ -5,7 +5,7 @@ source_filename = "main"
 %"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
 %main.stringStruct = type { ptr, i64 }
 %main.slice = type { ptr, i64, i64 }
-%"github.com/goplus/llgo/internal/runtime.iface" = type { ptr, ptr }
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
 
 @"main.init$guard" = global ptr null
 @main.minhexdigits = global ptr null
@@ -104,127 +104,272 @@ _llgo_0:
   call void @main.prinfsub(double 1.001000e+02)
   call void @main.printnl()
   %6 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 13)
-  %7 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %6, i64 1315859240)
-  call void @main.printany(%"github.com/goplus/llgo/internal/runtime.iface" %7)
+  %7 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %8 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %7, i32 0, i32 0
+  store ptr %6, ptr %8, align 8
+  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %7, i32 0, i32 1
+  store ptr inttoptr (i32 1315859240 to ptr), ptr %9, align 8
+  %10 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %7, align 8
+  call void @main.printany(%"github.com/goplus/llgo/internal/runtime.eface" %10)
   call void @main.printnl()
-  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 14)
-  %9 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %8, i64 4746175415993761792)
-  call void @main.printany(%"github.com/goplus/llgo/internal/runtime.iface" %9)
+  %11 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 14)
+  %12 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %13 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %12, i32 0, i32 0
+  store ptr %11, ptr %13, align 8
+  %14 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %12, i32 0, i32 1
+  store ptr inttoptr (i64 4746175415993761792 to ptr), ptr %14, align 8
+  %15 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %12, align 8
+  call void @main.printany(%"github.com/goplus/llgo/internal/runtime.eface" %15)
   call void @main.printnl()
   br i1 true, label %_llgo_3, label %_llgo_2
 
 _llgo_1:                                          ; preds = %_llgo_3
-  %10 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
-  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, i64 0
-  %12 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %13 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %12, i32 0, i32 0
-  store ptr @2, ptr %13, align 8
-  %14 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %12, i32 0, i32 1
-  store i64 10, ptr %14, align 4
-  %15 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %12, align 8
-  %16 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %15)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %16, ptr %11, align 8
-  %17 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, i64 1
-  %18 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
-  %19 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %18, i64 -1)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %19, ptr %17, align 8
-  %20 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %10, i64 16, i64 2, i64 0, i64 2, i64 2)
-  call void @main.println(%"github.com/goplus/llgo/internal/runtime.Slice" %20)
+  %16 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
+  %17 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %16, i64 0
+  %18 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %19 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %18, i32 0, i32 0
+  store ptr @2, ptr %19, align 8
+  %20 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %18, i32 0, i32 1
+  store i64 10, ptr %20, align 4
+  %21 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %18, align 8
+  %22 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %23 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %21, ptr %23, align 8
+  %24 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %25 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %24, i32 0, i32 0
+  store ptr %22, ptr %25, align 8
+  %26 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %24, i32 0, i32 1
+  store ptr %23, ptr %26, align 8
+  %27 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %24, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %27, ptr %17, align 8
+  %28 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %16, i64 1
+  %29 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
+  %30 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %31 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %30, i32 0, i32 0
+  store ptr %29, ptr %31, align 8
+  %32 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %30, i32 0, i32 1
+  store ptr inttoptr (i64 -1 to ptr), ptr %32, align 8
+  %33 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %30, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %33, ptr %28, align 8
+  %34 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %35 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %34, i32 0, i32 0
+  store ptr %16, ptr %35, align 8
+  %36 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %34, i32 0, i32 1
+  store i64 2, ptr %36, align 4
+  %37 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %34, i32 0, i32 2
+  store i64 2, ptr %37, align 4
+  %38 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %34, align 8
+  call void @main.println(%"github.com/goplus/llgo/internal/runtime.Slice" %38)
   br label %_llgo_2
 
 _llgo_2:                                          ; preds = %_llgo_3, %_llgo_1, %_llgo_0
-  %21 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 48)
-  %22 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %21, i64 0
-  %23 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %24 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %23, i32 0, i32 0
-  store ptr @3, ptr %24, align 8
-  %25 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %23, i32 0, i32 1
-  store i64 8, ptr %25, align 4
-  %26 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %23, align 8
-  %27 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %26)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %27, ptr %22, align 8
-  %28 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %21, i64 1
-  %29 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
-  %30 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %29, i64 -1)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %30, ptr %28, align 8
-  %31 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %21, i64 2
-  %32 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
-  %33 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %32, i64 -1)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %33, ptr %31, align 8
-  %34 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %21, i64 16, i64 3, i64 0, i64 3, i64 3)
-  call void @main.println(%"github.com/goplus/llgo/internal/runtime.Slice" %34)
-  %35 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 256)
-  %36 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 0
-  %37 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
-  %38 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %37, i64 -1)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %38, ptr %36, align 8
-  %39 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 1
-  %40 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
-  %41 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %40, i64 0)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %41, ptr %39, align 8
-  %42 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 2
-  %43 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 5)
-  %44 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %43, i64 97)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %44, ptr %42, align 8
-  %45 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 3
-  %46 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 5)
-  %47 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %46, i64 65)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %47, ptr %45, align 8
-  %48 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 4
-  %49 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 5)
-  %50 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %49, i64 20013)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %50, ptr %48, align 8
-  %51 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 5
-  %52 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 3)
-  %53 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %52, i64 1)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %53, ptr %51, align 8
-  %54 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 6
-  %55 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 4)
-  %56 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %55, i64 2)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %56, ptr %54, align 8
-  %57 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 7
-  %58 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 5)
-  %59 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %58, i64 3)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %59, ptr %57, align 8
-  %60 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 8
-  %61 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 6)
-  %62 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %61, i64 4)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %62, ptr %60, align 8
-  %63 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 9
-  %64 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
-  %65 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %64, i64 5)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %65, ptr %63, align 8
-  %66 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 10
-  %67 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 8)
-  %68 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %67, i64 1)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %68, ptr %66, align 8
-  %69 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 11
-  %70 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 9)
-  %71 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %70, i64 2)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %71, ptr %69, align 8
-  %72 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 12
-  %73 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 10)
-  %74 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %73, i64 3)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %74, ptr %72, align 8
-  %75 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 13
-  %76 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 11)
-  %77 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %76, i64 4)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %77, ptr %75, align 8
-  %78 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 14
-  %79 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 12)
-  %80 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %79, i64 5)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %80, ptr %78, align 8
-  %81 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %35, i64 15
-  %82 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %83 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %82, i32 0, i32 0
-  store ptr @4, ptr %83, align 8
-  %84 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %82, i32 0, i32 1
-  store i64 4, ptr %84, align 4
-  %85 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %82, align 8
-  %86 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %85)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %86, ptr %81, align 8
-  %87 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %35, i64 16, i64 16, i64 0, i64 16, i64 16)
-  call void @main.println(%"github.com/goplus/llgo/internal/runtime.Slice" %87)
+  %39 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 48)
+  %40 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %39, i64 0
+  %41 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %42 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %41, i32 0, i32 0
+  store ptr @3, ptr %42, align 8
+  %43 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %41, i32 0, i32 1
+  store i64 8, ptr %43, align 4
+  %44 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %41, align 8
+  %45 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %46 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %44, ptr %46, align 8
+  %47 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %48 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %47, i32 0, i32 0
+  store ptr %45, ptr %48, align 8
+  %49 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %47, i32 0, i32 1
+  store ptr %46, ptr %49, align 8
+  %50 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %47, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %50, ptr %40, align 8
+  %51 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %39, i64 1
+  %52 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
+  %53 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %54 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %53, i32 0, i32 0
+  store ptr %52, ptr %54, align 8
+  %55 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %53, i32 0, i32 1
+  store ptr inttoptr (i64 -1 to ptr), ptr %55, align 8
+  %56 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %53, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %56, ptr %51, align 8
+  %57 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %39, i64 2
+  %58 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
+  %59 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %60 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %59, i32 0, i32 0
+  store ptr %58, ptr %60, align 8
+  %61 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %59, i32 0, i32 1
+  store ptr inttoptr (i64 -1 to ptr), ptr %61, align 8
+  %62 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %59, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %62, ptr %57, align 8
+  %63 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %64 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %63, i32 0, i32 0
+  store ptr %39, ptr %64, align 8
+  %65 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %63, i32 0, i32 1
+  store i64 3, ptr %65, align 4
+  %66 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %63, i32 0, i32 2
+  store i64 3, ptr %66, align 4
+  %67 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %63, align 8
+  call void @main.println(%"github.com/goplus/llgo/internal/runtime.Slice" %67)
+  %68 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 256)
+  %69 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 0
+  %70 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
+  %71 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %72 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %71, i32 0, i32 0
+  store ptr %70, ptr %72, align 8
+  %73 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %71, i32 0, i32 1
+  store ptr inttoptr (i64 -1 to ptr), ptr %73, align 8
+  %74 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %71, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %74, ptr %69, align 8
+  %75 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 1
+  %76 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
+  %77 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %78 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %77, i32 0, i32 0
+  store ptr %76, ptr %78, align 8
+  %79 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %77, i32 0, i32 1
+  store ptr null, ptr %79, align 8
+  %80 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %77, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %80, ptr %75, align 8
+  %81 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 2
+  %82 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 5)
+  %83 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %84 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %83, i32 0, i32 0
+  store ptr %82, ptr %84, align 8
+  %85 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %83, i32 0, i32 1
+  store ptr inttoptr (i64 97 to ptr), ptr %85, align 8
+  %86 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %83, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %86, ptr %81, align 8
+  %87 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 3
+  %88 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 5)
+  %89 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %90 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %89, i32 0, i32 0
+  store ptr %88, ptr %90, align 8
+  %91 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %89, i32 0, i32 1
+  store ptr inttoptr (i64 65 to ptr), ptr %91, align 8
+  %92 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %89, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %92, ptr %87, align 8
+  %93 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 4
+  %94 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 5)
+  %95 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %96 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %95, i32 0, i32 0
+  store ptr %94, ptr %96, align 8
+  %97 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %95, i32 0, i32 1
+  store ptr inttoptr (i64 20013 to ptr), ptr %97, align 8
+  %98 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %95, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %98, ptr %93, align 8
+  %99 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 5
+  %100 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 3)
+  %101 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %102 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %101, i32 0, i32 0
+  store ptr %100, ptr %102, align 8
+  %103 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %101, i32 0, i32 1
+  store ptr inttoptr (i64 1 to ptr), ptr %103, align 8
+  %104 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %101, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %104, ptr %99, align 8
+  %105 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 6
+  %106 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 4)
+  %107 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %108 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %107, i32 0, i32 0
+  store ptr %106, ptr %108, align 8
+  %109 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %107, i32 0, i32 1
+  store ptr inttoptr (i64 2 to ptr), ptr %109, align 8
+  %110 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %107, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %110, ptr %105, align 8
+  %111 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 7
+  %112 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 5)
+  %113 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %114 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %113, i32 0, i32 0
+  store ptr %112, ptr %114, align 8
+  %115 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %113, i32 0, i32 1
+  store ptr inttoptr (i64 3 to ptr), ptr %115, align 8
+  %116 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %113, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %116, ptr %111, align 8
+  %117 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 8
+  %118 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 6)
+  %119 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %120 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %119, i32 0, i32 0
+  store ptr %118, ptr %120, align 8
+  %121 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %119, i32 0, i32 1
+  store ptr inttoptr (i64 4 to ptr), ptr %121, align 8
+  %122 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %119, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %122, ptr %117, align 8
+  %123 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 9
+  %124 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
+  %125 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %126 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %125, i32 0, i32 0
+  store ptr %124, ptr %126, align 8
+  %127 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %125, i32 0, i32 1
+  store ptr inttoptr (i64 5 to ptr), ptr %127, align 8
+  %128 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %125, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %128, ptr %123, align 8
+  %129 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 10
+  %130 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 8)
+  %131 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %132 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %131, i32 0, i32 0
+  store ptr %130, ptr %132, align 8
+  %133 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %131, i32 0, i32 1
+  store ptr inttoptr (i64 1 to ptr), ptr %133, align 8
+  %134 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %131, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %134, ptr %129, align 8
+  %135 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 11
+  %136 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 9)
+  %137 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %138 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %137, i32 0, i32 0
+  store ptr %136, ptr %138, align 8
+  %139 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %137, i32 0, i32 1
+  store ptr inttoptr (i64 2 to ptr), ptr %139, align 8
+  %140 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %137, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %140, ptr %135, align 8
+  %141 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 12
+  %142 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 10)
+  %143 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %144 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %143, i32 0, i32 0
+  store ptr %142, ptr %144, align 8
+  %145 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %143, i32 0, i32 1
+  store ptr inttoptr (i64 3 to ptr), ptr %145, align 8
+  %146 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %143, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %146, ptr %141, align 8
+  %147 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 13
+  %148 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 11)
+  %149 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %150 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %149, i32 0, i32 0
+  store ptr %148, ptr %150, align 8
+  %151 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %149, i32 0, i32 1
+  store ptr inttoptr (i64 4 to ptr), ptr %151, align 8
+  %152 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %149, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %152, ptr %147, align 8
+  %153 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 14
+  %154 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 12)
+  %155 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %156 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %155, i32 0, i32 0
+  store ptr %154, ptr %156, align 8
+  %157 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %155, i32 0, i32 1
+  store ptr inttoptr (i64 5 to ptr), ptr %157, align 8
+  %158 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %155, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %158, ptr %153, align 8
+  %159 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %68, i64 15
+  %160 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %161 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %160, i32 0, i32 0
+  store ptr @4, ptr %161, align 8
+  %162 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %160, i32 0, i32 1
+  store i64 4, ptr %162, align 4
+  %163 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %160, align 8
+  %164 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %165 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %163, ptr %165, align 8
+  %166 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %167 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %166, i32 0, i32 0
+  store ptr %164, ptr %167, align 8
+  %168 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %166, i32 0, i32 1
+  store ptr %165, ptr %168, align 8
+  %169 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %166, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %169, ptr %159, align 8
+  %170 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %171 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %170, i32 0, i32 0
+  store ptr %68, ptr %171, align 8
+  %172 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %170, i32 0, i32 1
+  store i64 16, ptr %172, align 4
+  %173 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %170, i32 0, i32 2
+  store i64 16, ptr %173, align 4
+  %174 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %170, align 8
+  call void @main.println(%"github.com/goplus/llgo/internal/runtime.Slice" %174)
   ret i32 0
 
 _llgo_3:                                          ; preds = %_llgo_0
@@ -245,190 +390,430 @@ _llgo_0:
   ret void
 }
 
-define void @main.printany(%"github.com/goplus/llgo/internal/runtime.iface" %0) {
+define void @main.printany(%"github.com/goplus/llgo/internal/runtime.eface" %0) {
 _llgo_0:
-  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
-  %2 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %1)
-  %3 = extractvalue { i64, i1 } %2, 0
-  %4 = trunc i64 %3 to i1
-  %5 = extractvalue { i64, i1 } %2, 1
-  br i1 %5, label %_llgo_2, label %_llgo_3
+  %1 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 1)
+  %3 = icmp eq ptr %1, %2
+  %4 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %5 = ptrtoint ptr %4 to i64
+  %6 = trunc i64 %5 to i1
+  %7 = alloca { i1, i1 }, align 8
+  %8 = getelementptr inbounds { i1, i1 }, ptr %7, i32 0, i32 0
+  store i1 %6, ptr %8, align 1
+  %9 = getelementptr inbounds { i1, i1 }, ptr %7, i32 0, i32 1
+  store i1 true, ptr %9, align 1
+  %10 = load { i1, i1 }, ptr %7, align 1
+  %11 = alloca { i1, i1 }, align 8
+  %12 = getelementptr inbounds { i1, i1 }, ptr %11, i32 0, i32 0
+  store i1 false, ptr %12, align 1
+  %13 = getelementptr inbounds { i1, i1 }, ptr %11, i32 0, i32 1
+  store i1 false, ptr %13, align 1
+  %14 = load { i1, i1 }, ptr %11, align 1
+  %15 = select i1 %3, { i1, i1 } %10, { i1, i1 } %14
+  %16 = extractvalue { i1, i1 } %15, 0
+  %17 = extractvalue { i1, i1 } %15, 1
+  br i1 %17, label %_llgo_2, label %_llgo_3
 
 _llgo_1:                                          ; preds = %_llgo_30, %_llgo_29, %_llgo_28, %_llgo_26, %_llgo_24, %_llgo_22, %_llgo_20, %_llgo_18, %_llgo_16, %_llgo_14, %_llgo_12, %_llgo_10, %_llgo_8, %_llgo_6, %_llgo_4, %_llgo_2
   ret void
 
 _llgo_2:                                          ; preds = %_llgo_0
-  call void @main.printbool(i1 %4)
+  call void @main.printbool(i1 %16)
   br label %_llgo_1
 
 _llgo_3:                                          ; preds = %_llgo_0
-  %6 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
-  %7 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %6)
-  %8 = extractvalue { i64, i1 } %7, 0
-  %9 = extractvalue { i64, i1 } %7, 1
-  br i1 %9, label %_llgo_4, label %_llgo_5
+  %18 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %19 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
+  %20 = icmp eq ptr %18, %19
+  %21 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %22 = ptrtoint ptr %21 to i64
+  %23 = alloca { i64, i1 }, align 8
+  %24 = getelementptr inbounds { i64, i1 }, ptr %23, i32 0, i32 0
+  store i64 %22, ptr %24, align 4
+  %25 = getelementptr inbounds { i64, i1 }, ptr %23, i32 0, i32 1
+  store i1 true, ptr %25, align 1
+  %26 = load { i64, i1 }, ptr %23, align 4
+  %27 = alloca { i64, i1 }, align 8
+  %28 = getelementptr inbounds { i64, i1 }, ptr %27, i32 0, i32 0
+  store i64 0, ptr %28, align 4
+  %29 = getelementptr inbounds { i64, i1 }, ptr %27, i32 0, i32 1
+  store i1 false, ptr %29, align 1
+  %30 = load { i64, i1 }, ptr %27, align 4
+  %31 = select i1 %20, { i64, i1 } %26, { i64, i1 } %30
+  %32 = extractvalue { i64, i1 } %31, 0
+  %33 = extractvalue { i64, i1 } %31, 1
+  br i1 %33, label %_llgo_4, label %_llgo_5
 
 _llgo_4:                                          ; preds = %_llgo_3
-  call void @main.printint(i64 %8)
+  call void @main.printint(i64 %32)
   br label %_llgo_1
 
 _llgo_5:                                          ; preds = %_llgo_3
-  %10 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 3)
-  %11 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %10)
-  %12 = extractvalue { i64, i1 } %11, 0
-  %13 = trunc i64 %12 to i8
-  %14 = extractvalue { i64, i1 } %11, 1
-  br i1 %14, label %_llgo_6, label %_llgo_7
+  %34 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %35 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 3)
+  %36 = icmp eq ptr %34, %35
+  %37 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %38 = ptrtoint ptr %37 to i64
+  %39 = trunc i64 %38 to i8
+  %40 = alloca { i8, i1 }, align 8
+  %41 = getelementptr inbounds { i8, i1 }, ptr %40, i32 0, i32 0
+  store i8 %39, ptr %41, align 1
+  %42 = getelementptr inbounds { i8, i1 }, ptr %40, i32 0, i32 1
+  store i1 true, ptr %42, align 1
+  %43 = load { i8, i1 }, ptr %40, align 1
+  %44 = alloca { i8, i1 }, align 8
+  %45 = getelementptr inbounds { i8, i1 }, ptr %44, i32 0, i32 0
+  store i8 0, ptr %45, align 1
+  %46 = getelementptr inbounds { i8, i1 }, ptr %44, i32 0, i32 1
+  store i1 false, ptr %46, align 1
+  %47 = load { i8, i1 }, ptr %44, align 1
+  %48 = select i1 %36, { i8, i1 } %43, { i8, i1 } %47
+  %49 = extractvalue { i8, i1 } %48, 0
+  %50 = extractvalue { i8, i1 } %48, 1
+  br i1 %50, label %_llgo_6, label %_llgo_7
 
 _llgo_6:                                          ; preds = %_llgo_5
-  %15 = sext i8 %13 to i64
-  call void @main.printint(i64 %15)
+  %51 = sext i8 %49 to i64
+  call void @main.printint(i64 %51)
   br label %_llgo_1
 
 _llgo_7:                                          ; preds = %_llgo_5
-  %16 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 4)
-  %17 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %16)
-  %18 = extractvalue { i64, i1 } %17, 0
-  %19 = trunc i64 %18 to i16
-  %20 = extractvalue { i64, i1 } %17, 1
-  br i1 %20, label %_llgo_8, label %_llgo_9
+  %52 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %53 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 4)
+  %54 = icmp eq ptr %52, %53
+  %55 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %56 = ptrtoint ptr %55 to i64
+  %57 = trunc i64 %56 to i16
+  %58 = alloca { i16, i1 }, align 8
+  %59 = getelementptr inbounds { i16, i1 }, ptr %58, i32 0, i32 0
+  store i16 %57, ptr %59, align 2
+  %60 = getelementptr inbounds { i16, i1 }, ptr %58, i32 0, i32 1
+  store i1 true, ptr %60, align 1
+  %61 = load { i16, i1 }, ptr %58, align 2
+  %62 = alloca { i16, i1 }, align 8
+  %63 = getelementptr inbounds { i16, i1 }, ptr %62, i32 0, i32 0
+  store i16 0, ptr %63, align 2
+  %64 = getelementptr inbounds { i16, i1 }, ptr %62, i32 0, i32 1
+  store i1 false, ptr %64, align 1
+  %65 = load { i16, i1 }, ptr %62, align 2
+  %66 = select i1 %54, { i16, i1 } %61, { i16, i1 } %65
+  %67 = extractvalue { i16, i1 } %66, 0
+  %68 = extractvalue { i16, i1 } %66, 1
+  br i1 %68, label %_llgo_8, label %_llgo_9
 
 _llgo_8:                                          ; preds = %_llgo_7
-  %21 = sext i16 %19 to i64
-  call void @main.printint(i64 %21)
+  %69 = sext i16 %67 to i64
+  call void @main.printint(i64 %69)
   br label %_llgo_1
 
 _llgo_9:                                          ; preds = %_llgo_7
-  %22 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 5)
-  %23 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %22)
-  %24 = extractvalue { i64, i1 } %23, 0
-  %25 = trunc i64 %24 to i32
-  %26 = extractvalue { i64, i1 } %23, 1
-  br i1 %26, label %_llgo_10, label %_llgo_11
+  %70 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %71 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 5)
+  %72 = icmp eq ptr %70, %71
+  %73 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %74 = ptrtoint ptr %73 to i64
+  %75 = trunc i64 %74 to i32
+  %76 = alloca { i32, i1 }, align 8
+  %77 = getelementptr inbounds { i32, i1 }, ptr %76, i32 0, i32 0
+  store i32 %75, ptr %77, align 4
+  %78 = getelementptr inbounds { i32, i1 }, ptr %76, i32 0, i32 1
+  store i1 true, ptr %78, align 1
+  %79 = load { i32, i1 }, ptr %76, align 4
+  %80 = alloca { i32, i1 }, align 8
+  %81 = getelementptr inbounds { i32, i1 }, ptr %80, i32 0, i32 0
+  store i32 0, ptr %81, align 4
+  %82 = getelementptr inbounds { i32, i1 }, ptr %80, i32 0, i32 1
+  store i1 false, ptr %82, align 1
+  %83 = load { i32, i1 }, ptr %80, align 4
+  %84 = select i1 %72, { i32, i1 } %79, { i32, i1 } %83
+  %85 = extractvalue { i32, i1 } %84, 0
+  %86 = extractvalue { i32, i1 } %84, 1
+  br i1 %86, label %_llgo_10, label %_llgo_11
 
 _llgo_10:                                         ; preds = %_llgo_9
-  %27 = sext i32 %25 to i64
-  call void @main.printint(i64 %27)
+  %87 = sext i32 %85 to i64
+  call void @main.printint(i64 %87)
   br label %_llgo_1
 
 _llgo_11:                                         ; preds = %_llgo_9
-  %28 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 6)
-  %29 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %28)
-  %30 = extractvalue { i64, i1 } %29, 0
-  %31 = extractvalue { i64, i1 } %29, 1
-  br i1 %31, label %_llgo_12, label %_llgo_13
+  %88 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %89 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 6)
+  %90 = icmp eq ptr %88, %89
+  %91 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %92 = ptrtoint ptr %91 to i64
+  %93 = alloca { i64, i1 }, align 8
+  %94 = getelementptr inbounds { i64, i1 }, ptr %93, i32 0, i32 0
+  store i64 %92, ptr %94, align 4
+  %95 = getelementptr inbounds { i64, i1 }, ptr %93, i32 0, i32 1
+  store i1 true, ptr %95, align 1
+  %96 = load { i64, i1 }, ptr %93, align 4
+  %97 = alloca { i64, i1 }, align 8
+  %98 = getelementptr inbounds { i64, i1 }, ptr %97, i32 0, i32 0
+  store i64 0, ptr %98, align 4
+  %99 = getelementptr inbounds { i64, i1 }, ptr %97, i32 0, i32 1
+  store i1 false, ptr %99, align 1
+  %100 = load { i64, i1 }, ptr %97, align 4
+  %101 = select i1 %90, { i64, i1 } %96, { i64, i1 } %100
+  %102 = extractvalue { i64, i1 } %101, 0
+  %103 = extractvalue { i64, i1 } %101, 1
+  br i1 %103, label %_llgo_12, label %_llgo_13
 
 _llgo_12:                                         ; preds = %_llgo_11
-  call void @main.printint(i64 %30)
+  call void @main.printint(i64 %102)
   br label %_llgo_1
 
 _llgo_13:                                         ; preds = %_llgo_11
-  %32 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 7)
-  %33 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %32)
-  %34 = extractvalue { i64, i1 } %33, 0
-  %35 = extractvalue { i64, i1 } %33, 1
-  br i1 %35, label %_llgo_14, label %_llgo_15
+  %104 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %105 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 7)
+  %106 = icmp eq ptr %104, %105
+  %107 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %108 = ptrtoint ptr %107 to i64
+  %109 = alloca { i64, i1 }, align 8
+  %110 = getelementptr inbounds { i64, i1 }, ptr %109, i32 0, i32 0
+  store i64 %108, ptr %110, align 4
+  %111 = getelementptr inbounds { i64, i1 }, ptr %109, i32 0, i32 1
+  store i1 true, ptr %111, align 1
+  %112 = load { i64, i1 }, ptr %109, align 4
+  %113 = alloca { i64, i1 }, align 8
+  %114 = getelementptr inbounds { i64, i1 }, ptr %113, i32 0, i32 0
+  store i64 0, ptr %114, align 4
+  %115 = getelementptr inbounds { i64, i1 }, ptr %113, i32 0, i32 1
+  store i1 false, ptr %115, align 1
+  %116 = load { i64, i1 }, ptr %113, align 4
+  %117 = select i1 %106, { i64, i1 } %112, { i64, i1 } %116
+  %118 = extractvalue { i64, i1 } %117, 0
+  %119 = extractvalue { i64, i1 } %117, 1
+  br i1 %119, label %_llgo_14, label %_llgo_15
 
 _llgo_14:                                         ; preds = %_llgo_13
-  call void @main.printuint(i64 %34)
+  call void @main.printuint(i64 %118)
   br label %_llgo_1
 
 _llgo_15:                                         ; preds = %_llgo_13
-  %36 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 8)
-  %37 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %36)
-  %38 = extractvalue { i64, i1 } %37, 0
-  %39 = trunc i64 %38 to i8
-  %40 = extractvalue { i64, i1 } %37, 1
-  br i1 %40, label %_llgo_16, label %_llgo_17
+  %120 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %121 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 8)
+  %122 = icmp eq ptr %120, %121
+  %123 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %124 = ptrtoint ptr %123 to i64
+  %125 = trunc i64 %124 to i8
+  %126 = alloca { i8, i1 }, align 8
+  %127 = getelementptr inbounds { i8, i1 }, ptr %126, i32 0, i32 0
+  store i8 %125, ptr %127, align 1
+  %128 = getelementptr inbounds { i8, i1 }, ptr %126, i32 0, i32 1
+  store i1 true, ptr %128, align 1
+  %129 = load { i8, i1 }, ptr %126, align 1
+  %130 = alloca { i8, i1 }, align 8
+  %131 = getelementptr inbounds { i8, i1 }, ptr %130, i32 0, i32 0
+  store i8 0, ptr %131, align 1
+  %132 = getelementptr inbounds { i8, i1 }, ptr %130, i32 0, i32 1
+  store i1 false, ptr %132, align 1
+  %133 = load { i8, i1 }, ptr %130, align 1
+  %134 = select i1 %122, { i8, i1 } %129, { i8, i1 } %133
+  %135 = extractvalue { i8, i1 } %134, 0
+  %136 = extractvalue { i8, i1 } %134, 1
+  br i1 %136, label %_llgo_16, label %_llgo_17
 
 _llgo_16:                                         ; preds = %_llgo_15
-  %41 = zext i8 %39 to i64
-  call void @main.printuint(i64 %41)
+  %137 = zext i8 %135 to i64
+  call void @main.printuint(i64 %137)
   br label %_llgo_1
 
 _llgo_17:                                         ; preds = %_llgo_15
-  %42 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 9)
-  %43 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %42)
-  %44 = extractvalue { i64, i1 } %43, 0
-  %45 = trunc i64 %44 to i16
-  %46 = extractvalue { i64, i1 } %43, 1
-  br i1 %46, label %_llgo_18, label %_llgo_19
+  %138 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %139 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 9)
+  %140 = icmp eq ptr %138, %139
+  %141 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %142 = ptrtoint ptr %141 to i64
+  %143 = trunc i64 %142 to i16
+  %144 = alloca { i16, i1 }, align 8
+  %145 = getelementptr inbounds { i16, i1 }, ptr %144, i32 0, i32 0
+  store i16 %143, ptr %145, align 2
+  %146 = getelementptr inbounds { i16, i1 }, ptr %144, i32 0, i32 1
+  store i1 true, ptr %146, align 1
+  %147 = load { i16, i1 }, ptr %144, align 2
+  %148 = alloca { i16, i1 }, align 8
+  %149 = getelementptr inbounds { i16, i1 }, ptr %148, i32 0, i32 0
+  store i16 0, ptr %149, align 2
+  %150 = getelementptr inbounds { i16, i1 }, ptr %148, i32 0, i32 1
+  store i1 false, ptr %150, align 1
+  %151 = load { i16, i1 }, ptr %148, align 2
+  %152 = select i1 %140, { i16, i1 } %147, { i16, i1 } %151
+  %153 = extractvalue { i16, i1 } %152, 0
+  %154 = extractvalue { i16, i1 } %152, 1
+  br i1 %154, label %_llgo_18, label %_llgo_19
 
 _llgo_18:                                         ; preds = %_llgo_17
-  %47 = zext i16 %45 to i64
-  call void @main.printuint(i64 %47)
+  %155 = zext i16 %153 to i64
+  call void @main.printuint(i64 %155)
   br label %_llgo_1
 
 _llgo_19:                                         ; preds = %_llgo_17
-  %48 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 10)
-  %49 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %48)
-  %50 = extractvalue { i64, i1 } %49, 0
-  %51 = trunc i64 %50 to i32
-  %52 = extractvalue { i64, i1 } %49, 1
-  br i1 %52, label %_llgo_20, label %_llgo_21
+  %156 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %157 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 10)
+  %158 = icmp eq ptr %156, %157
+  %159 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %160 = ptrtoint ptr %159 to i64
+  %161 = trunc i64 %160 to i32
+  %162 = alloca { i32, i1 }, align 8
+  %163 = getelementptr inbounds { i32, i1 }, ptr %162, i32 0, i32 0
+  store i32 %161, ptr %163, align 4
+  %164 = getelementptr inbounds { i32, i1 }, ptr %162, i32 0, i32 1
+  store i1 true, ptr %164, align 1
+  %165 = load { i32, i1 }, ptr %162, align 4
+  %166 = alloca { i32, i1 }, align 8
+  %167 = getelementptr inbounds { i32, i1 }, ptr %166, i32 0, i32 0
+  store i32 0, ptr %167, align 4
+  %168 = getelementptr inbounds { i32, i1 }, ptr %166, i32 0, i32 1
+  store i1 false, ptr %168, align 1
+  %169 = load { i32, i1 }, ptr %166, align 4
+  %170 = select i1 %158, { i32, i1 } %165, { i32, i1 } %169
+  %171 = extractvalue { i32, i1 } %170, 0
+  %172 = extractvalue { i32, i1 } %170, 1
+  br i1 %172, label %_llgo_20, label %_llgo_21
 
 _llgo_20:                                         ; preds = %_llgo_19
-  %53 = zext i32 %51 to i64
-  call void @main.printuint(i64 %53)
+  %173 = zext i32 %171 to i64
+  call void @main.printuint(i64 %173)
   br label %_llgo_1
 
 _llgo_21:                                         ; preds = %_llgo_19
-  %54 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 11)
-  %55 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %54)
-  %56 = extractvalue { i64, i1 } %55, 0
-  %57 = extractvalue { i64, i1 } %55, 1
-  br i1 %57, label %_llgo_22, label %_llgo_23
+  %174 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %175 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 11)
+  %176 = icmp eq ptr %174, %175
+  %177 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %178 = ptrtoint ptr %177 to i64
+  %179 = alloca { i64, i1 }, align 8
+  %180 = getelementptr inbounds { i64, i1 }, ptr %179, i32 0, i32 0
+  store i64 %178, ptr %180, align 4
+  %181 = getelementptr inbounds { i64, i1 }, ptr %179, i32 0, i32 1
+  store i1 true, ptr %181, align 1
+  %182 = load { i64, i1 }, ptr %179, align 4
+  %183 = alloca { i64, i1 }, align 8
+  %184 = getelementptr inbounds { i64, i1 }, ptr %183, i32 0, i32 0
+  store i64 0, ptr %184, align 4
+  %185 = getelementptr inbounds { i64, i1 }, ptr %183, i32 0, i32 1
+  store i1 false, ptr %185, align 1
+  %186 = load { i64, i1 }, ptr %183, align 4
+  %187 = select i1 %176, { i64, i1 } %182, { i64, i1 } %186
+  %188 = extractvalue { i64, i1 } %187, 0
+  %189 = extractvalue { i64, i1 } %187, 1
+  br i1 %189, label %_llgo_22, label %_llgo_23
 
 _llgo_22:                                         ; preds = %_llgo_21
-  call void @main.printuint(i64 %56)
+  call void @main.printuint(i64 %188)
   br label %_llgo_1
 
 _llgo_23:                                         ; preds = %_llgo_21
-  %58 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 12)
-  %59 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %58)
-  %60 = extractvalue { i64, i1 } %59, 0
-  %61 = extractvalue { i64, i1 } %59, 1
-  br i1 %61, label %_llgo_24, label %_llgo_25
+  %190 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %191 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 12)
+  %192 = icmp eq ptr %190, %191
+  %193 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %194 = ptrtoint ptr %193 to i64
+  %195 = alloca { i64, i1 }, align 8
+  %196 = getelementptr inbounds { i64, i1 }, ptr %195, i32 0, i32 0
+  store i64 %194, ptr %196, align 4
+  %197 = getelementptr inbounds { i64, i1 }, ptr %195, i32 0, i32 1
+  store i1 true, ptr %197, align 1
+  %198 = load { i64, i1 }, ptr %195, align 4
+  %199 = alloca { i64, i1 }, align 8
+  %200 = getelementptr inbounds { i64, i1 }, ptr %199, i32 0, i32 0
+  store i64 0, ptr %200, align 4
+  %201 = getelementptr inbounds { i64, i1 }, ptr %199, i32 0, i32 1
+  store i1 false, ptr %201, align 1
+  %202 = load { i64, i1 }, ptr %199, align 4
+  %203 = select i1 %192, { i64, i1 } %198, { i64, i1 } %202
+  %204 = extractvalue { i64, i1 } %203, 0
+  %205 = extractvalue { i64, i1 } %203, 1
+  br i1 %205, label %_llgo_24, label %_llgo_25
 
 _llgo_24:                                         ; preds = %_llgo_23
-  call void @main.printuint(i64 %60)
+  call void @main.printuint(i64 %204)
   br label %_llgo_1
 
 _llgo_25:                                         ; preds = %_llgo_23
-  %62 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 13)
-  %63 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %62)
-  %64 = extractvalue { i64, i1 } %63, 0
-  %65 = trunc i64 %64 to i32
-  %66 = bitcast i32 %65 to float
-  %67 = extractvalue { i64, i1 } %63, 1
-  br i1 %67, label %_llgo_26, label %_llgo_27
+  %206 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %207 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 13)
+  %208 = icmp eq ptr %206, %207
+  %209 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %210 = ptrtoint ptr %209 to i64
+  %211 = trunc i64 %210 to i32
+  %212 = bitcast i32 %211 to float
+  %213 = alloca { float, i1 }, align 8
+  %214 = getelementptr inbounds { float, i1 }, ptr %213, i32 0, i32 0
+  store float %212, ptr %214, align 4
+  %215 = getelementptr inbounds { float, i1 }, ptr %213, i32 0, i32 1
+  store i1 true, ptr %215, align 1
+  %216 = load { float, i1 }, ptr %213, align 4
+  %217 = alloca { float, i1 }, align 8
+  %218 = getelementptr inbounds { float, i1 }, ptr %217, i32 0, i32 0
+  store double 0.000000e+00, ptr %218, align 8
+  %219 = getelementptr inbounds { float, i1 }, ptr %217, i32 0, i32 1
+  store i1 false, ptr %219, align 1
+  %220 = load { float, i1 }, ptr %217, align 4
+  %221 = select i1 %208, { float, i1 } %216, { float, i1 } %220
+  %222 = extractvalue { float, i1 } %221, 0
+  %223 = extractvalue { float, i1 } %221, 1
+  br i1 %223, label %_llgo_26, label %_llgo_27
 
 _llgo_26:                                         ; preds = %_llgo_25
-  %68 = fpext float %66 to double
-  call void @main.printfloat(double %68)
+  %224 = fpext float %222 to double
+  call void @main.printfloat(double %224)
   br label %_llgo_1
 
 _llgo_27:                                         ; preds = %_llgo_25
-  %69 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 14)
-  %70 = call { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %69)
-  %71 = extractvalue { i64, i1 } %70, 0
-  %72 = bitcast i64 %71 to double
-  %73 = extractvalue { i64, i1 } %70, 1
-  br i1 %73, label %_llgo_28, label %_llgo_29
+  %225 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %226 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 14)
+  %227 = icmp eq ptr %225, %226
+  %228 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %229 = ptrtoint ptr %228 to i64
+  %230 = bitcast i64 %229 to double
+  %231 = alloca { double, i1 }, align 8
+  %232 = getelementptr inbounds { double, i1 }, ptr %231, i32 0, i32 0
+  store double %230, ptr %232, align 8
+  %233 = getelementptr inbounds { double, i1 }, ptr %231, i32 0, i32 1
+  store i1 true, ptr %233, align 1
+  %234 = load { double, i1 }, ptr %231, align 8
+  %235 = alloca { double, i1 }, align 8
+  %236 = getelementptr inbounds { double, i1 }, ptr %235, i32 0, i32 0
+  store double 0.000000e+00, ptr %236, align 8
+  %237 = getelementptr inbounds { double, i1 }, ptr %235, i32 0, i32 1
+  store i1 false, ptr %237, align 1
+  %238 = load { double, i1 }, ptr %235, align 8
+  %239 = select i1 %227, { double, i1 } %234, { double, i1 } %238
+  %240 = extractvalue { double, i1 } %239, 0
+  %241 = extractvalue { double, i1 } %239, 1
+  br i1 %241, label %_llgo_28, label %_llgo_29
 
 _llgo_28:                                         ; preds = %_llgo_27
-  call void @main.printfloat(double %72)
+  call void @main.printfloat(double %240)
   br label %_llgo_1
 
 _llgo_29:                                         ; preds = %_llgo_27
-  %74 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
-  %75 = call { %"github.com/goplus/llgo/internal/runtime.String", i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2String"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %74)
-  %76 = extractvalue { %"github.com/goplus/llgo/internal/runtime.String", i1 } %75, 0
-  %77 = extractvalue { %"github.com/goplus/llgo/internal/runtime.String", i1 } %75, 1
-  br i1 %77, label %_llgo_30, label %_llgo_1
+  %242 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %243 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %244 = icmp eq ptr %242, %243
+  %245 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %246 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %245, align 8
+  %247 = alloca { %"github.com/goplus/llgo/internal/runtime.String", i1 }, align 8
+  %248 = getelementptr inbounds { %"github.com/goplus/llgo/internal/runtime.String", i1 }, ptr %247, i32 0, i32 0
+  store %"github.com/goplus/llgo/internal/runtime.String" %246, ptr %248, align 8
+  %249 = getelementptr inbounds { %"github.com/goplus/llgo/internal/runtime.String", i1 }, ptr %247, i32 0, i32 1
+  store i1 true, ptr %249, align 1
+  %250 = load { %"github.com/goplus/llgo/internal/runtime.String", i1 }, ptr %247, align 8
+  %251 = alloca { %"github.com/goplus/llgo/internal/runtime.String", i1 }, align 8
+  %252 = getelementptr inbounds { %"github.com/goplus/llgo/internal/runtime.String", i1 }, ptr %251, i32 0, i32 0
+  store { ptr, i64 } zeroinitializer, ptr %252, align 8
+  %253 = getelementptr inbounds { %"github.com/goplus/llgo/internal/runtime.String", i1 }, ptr %251, i32 0, i32 1
+  store i1 false, ptr %253, align 1
+  %254 = load { %"github.com/goplus/llgo/internal/runtime.String", i1 }, ptr %251, align 8
+  %255 = select i1 %244, { %"github.com/goplus/llgo/internal/runtime.String", i1 } %250, { %"github.com/goplus/llgo/internal/runtime.String", i1 } %254
+  %256 = extractvalue { %"github.com/goplus/llgo/internal/runtime.String", i1 } %255, 0
+  %257 = extractvalue { %"github.com/goplus/llgo/internal/runtime.String", i1 } %255, 1
+  br i1 %257, label %_llgo_30, label %_llgo_1
 
 _llgo_30:                                         ; preds = %_llgo_29
-  call void @main.printstring(%"github.com/goplus/llgo/internal/runtime.String" %76)
+  call void @main.printstring(%"github.com/goplus/llgo/internal/runtime.String" %256)
   br label %_llgo_1
 }
 
@@ -658,8 +1043,15 @@ _llgo_29:                                         ; preds = %_llgo_28, %_llgo_26
   %86 = add i8 %85, 48
   %87 = getelementptr inbounds i8, ptr %20, i64 13
   store i8 %86, ptr %87, align 1
-  %88 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %20, i64 1, i64 14, i64 0, i64 14, i64 14)
-  call void @main.gwrite(%"github.com/goplus/llgo/internal/runtime.Slice" %88)
+  %88 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %89 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %88, i32 0, i32 0
+  store ptr %20, ptr %89, align 8
+  %90 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %88, i32 0, i32 1
+  store i64 14, ptr %90, align 4
+  %91 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %88, i32 0, i32 2
+  store i64 14, ptr %91, align 4
+  %92 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %88, align 8
+  call void @main.gwrite(%"github.com/goplus/llgo/internal/runtime.Slice" %92)
   ret void
 }
 
@@ -756,8 +1148,8 @@ _llgo_2:                                          ; preds = %_llgo_1
   %5 = icmp slt i64 %3, 0
   call void @"github.com/goplus/llgo/internal/runtime.AssertIndexRange"(i1 %5)
   %6 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %0, 0
-  %7 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %6, i64 %3
-  %8 = load %"github.com/goplus/llgo/internal/runtime.iface", ptr %7, align 8
+  %7 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %6, i64 %3
+  %8 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %7, align 8
   %9 = icmp ne i64 %3, 0
   br i1 %9, label %_llgo_4, label %_llgo_5
 
@@ -776,7 +1168,7 @@ _llgo_4:                                          ; preds = %_llgo_2
   br label %_llgo_5
 
 _llgo_5:                                          ; preds = %_llgo_4, %_llgo_2
-  call void @main.printany(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  call void @main.printany(%"github.com/goplus/llgo/internal/runtime.eface" %8)
   br label %_llgo_1
 }
 
@@ -869,16 +1261,10 @@ declare i32 @printf(ptr, ...)
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
-declare %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr, i64)
-
 declare ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64)
 
-declare %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String")
-
-declare %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr, i64, i64, i64, i64, i64)
-
-declare { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface", ptr)
-
-declare { %"github.com/goplus/llgo/internal/runtime.String", i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2String"(%"github.com/goplus/llgo/internal/runtime.iface", ptr)
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64)
 
 declare void @"github.com/goplus/llgo/internal/runtime.AssertIndexRange"(i1)
+
+declare %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr, i64, i64, i64, i64, i64)
diff --git a/cl/_testdata/vargs/out.ll b/cl/_testdata/vargs/out.ll
index 86c098c9..9d9d841e 100644
--- a/cl/_testdata/vargs/out.ll
+++ b/cl/_testdata/vargs/out.ll
@@ -1,13 +1,15 @@
 ; ModuleID = 'main'
 source_filename = "main"
 
-%"github.com/goplus/llgo/internal/runtime.iface" = type { ptr, ptr }
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
 %"github.com/goplus/llgo/internal/runtime.Slice" = type { ptr, i64, i64 }
+%"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
 
 @"main.init$guard" = global ptr null
 @__llgo_argc = global ptr null
 @__llgo_argv = global ptr null
 @0 = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
+@1 = private unnamed_addr constant [22 x i8] c"type assertion failed\00", align 1
 
 define void @main.init() {
 _llgo_0:
@@ -29,20 +31,42 @@ _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
   %2 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 48)
-  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %2, i64 0
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %2, i64 0
   %4 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
-  %5 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %4, i64 1)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %5, ptr %3, align 8
-  %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %2, i64 1
-  %7 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %7, i64 2)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %8, ptr %6, align 8
-  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %2, i64 2
+  %5 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %5, i32 0, i32 0
+  store ptr %4, ptr %6, align 8
+  %7 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %5, i32 0, i32 1
+  store ptr inttoptr (i64 1 to ptr), ptr %7, align 8
+  %8 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %5, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %8, ptr %3, align 8
+  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %2, i64 1
   %10 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
-  %11 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %10, i64 3)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %11, ptr %9, align 8
-  %12 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %2, i64 16, i64 3, i64 0, i64 3, i64 3)
-  call void @main.test(%"github.com/goplus/llgo/internal/runtime.Slice" %12)
+  %11 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %11, i32 0, i32 0
+  store ptr %10, ptr %12, align 8
+  %13 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %11, i32 0, i32 1
+  store ptr inttoptr (i64 2 to ptr), ptr %13, align 8
+  %14 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %11, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %14, ptr %9, align 8
+  %15 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %2, i64 2
+  %16 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
+  %17 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %18 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %17, i32 0, i32 0
+  store ptr %16, ptr %18, align 8
+  %19 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %17, i32 0, i32 1
+  store ptr inttoptr (i64 3 to ptr), ptr %19, align 8
+  %20 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %17, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %20, ptr %15, align 8
+  %21 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %22 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %21, i32 0, i32 0
+  store ptr %2, ptr %22, align 8
+  %23 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %21, i32 0, i32 1
+  store i64 3, ptr %23, align 4
+  %24 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %21, i32 0, i32 2
+  store i64 3, ptr %24, align 4
+  %25 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %21, align 8
+  call void @main.test(%"github.com/goplus/llgo/internal/runtime.Slice" %25)
   ret i32 0
 }
 
@@ -51,8 +75,8 @@ _llgo_0:
   %1 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %0, 1
   br label %_llgo_1
 
-_llgo_1:                                          ; preds = %_llgo_2, %_llgo_0
-  %2 = phi i64 [ -1, %_llgo_0 ], [ %3, %_llgo_2 ]
+_llgo_1:                                          ; preds = %_llgo_4, %_llgo_0
+  %2 = phi i64 [ -1, %_llgo_0 ], [ %3, %_llgo_4 ]
   %3 = add i64 %2, 1
   %4 = icmp slt i64 %3, %1
   br i1 %4, label %_llgo_2, label %_llgo_3
@@ -61,29 +85,41 @@ _llgo_2:                                          ; preds = %_llgo_1
   %5 = icmp slt i64 %3, 0
   call void @"github.com/goplus/llgo/internal/runtime.AssertIndexRange"(i1 %5)
   %6 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %0, 0
-  %7 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %6, i64 %3
-  %8 = load %"github.com/goplus/llgo/internal/runtime.iface", ptr %7, align 8
-  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
-  %10 = call i64 @"github.com/goplus/llgo/internal/runtime.I2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %8, ptr %9)
-  %11 = call i32 (ptr, ...) @printf(ptr @0, i64 %10)
-  br label %_llgo_1
+  %7 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %6, i64 %3
+  %8 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %7, align 8
+  %9 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %8, 0
+  %10 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
+  %11 = icmp eq ptr %9, %10
+  br i1 %11, label %_llgo_4, label %_llgo_5
 
 _llgo_3:                                          ; preds = %_llgo_1
   ret void
+
+_llgo_4:                                          ; preds = %_llgo_2
+  %12 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %8, 1
+  %13 = ptrtoint ptr %12 to i64
+  %14 = call i32 (ptr, ...) @printf(ptr @0, i64 %13)
+  br label %_llgo_1
+
+_llgo_5:                                          ; preds = %_llgo_2
+  %15 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %16 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %15, i32 0, i32 0
+  store ptr @1, ptr %16, align 8
+  %17 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %15, i32 0, i32 1
+  store i64 21, ptr %17, align 4
+  %18 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %15, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.String" %18)
+  unreachable
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
 declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
 
-declare %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr, i64)
-
 declare ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64)
 
-declare %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr, i64, i64, i64, i64, i64)
-
 declare void @"github.com/goplus/llgo/internal/runtime.AssertIndexRange"(i1)
 
-declare i64 @"github.com/goplus/llgo/internal/runtime.I2Int"(%"github.com/goplus/llgo/internal/runtime.iface", ptr)
+declare void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface")
 
 declare i32 @printf(ptr, ...)
diff --git a/cl/_testgo/strucintf/in.go b/cl/_testgo/strucintf/in.go
new file mode 100644
index 00000000..1af4b02d
--- /dev/null
+++ b/cl/_testgo/strucintf/in.go
@@ -0,0 +1,20 @@
+package main
+
+import (
+	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/cl/internal/foo"
+)
+
+func main() {
+	bar := foo.Bar()
+	if x, ok := bar.(struct{ V int }); ok {
+		c.Printf(c.Str("%d\n"), x.V)
+	} else {
+		c.Printf(c.Str("Bar: not ok\n"))
+	}
+	if x, ok := foo.F().(struct{ v int }); ok {
+		c.Printf(c.Str("%d\n"), x.v)
+	} else {
+		c.Printf(c.Str("F: not ok\n"))
+	}
+}
diff --git a/cl/_testgo/strucintf/out.ll b/cl/_testgo/strucintf/out.ll
new file mode 100644
index 00000000..57492612
--- /dev/null
+++ b/cl/_testgo/strucintf/out.ll
@@ -0,0 +1,229 @@
+; ModuleID = 'main'
+source_filename = "main"
+
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
+%"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
+%"github.com/goplus/llgo/internal/abi.StructField" = type { %"github.com/goplus/llgo/internal/abi.Name", ptr, i64 }
+%"github.com/goplus/llgo/internal/abi.Name" = type { ptr }
+%"github.com/goplus/llgo/internal/runtime.Slice" = type { ptr, i64, i64 }
+
+@"main.init$guard" = global ptr null
+@__llgo_argc = global ptr null
+@__llgo_argv = global ptr null
+@"_llgo_struct$K-dZ9QotZfVPz2a0YdRa9vmZUuDXPTqZOlMShKEDJtk" = linkonce global ptr null
+@0 = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
+@"main.struct$MYpsoM99ZwFY087IpUOkIw1zjBA_sgFXVodmn1m-G88" = global ptr null
+@1 = private unnamed_addr constant [13 x i8] c"Bar: not ok\0A\00", align 1
+@2 = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
+@3 = private unnamed_addr constant [11 x i8] c"F: not ok\0A\00", align 1
+@4 = private unnamed_addr constant [2 x i8] c"V\00", align 1
+@5 = private unnamed_addr constant [1 x i8] zeroinitializer, align 1
+@6 = private unnamed_addr constant [5 x i8] c"main\00", align 1
+@7 = private unnamed_addr constant [2 x i8] c"v\00", align 1
+@8 = private unnamed_addr constant [1 x i8] zeroinitializer, align 1
+@9 = private unnamed_addr constant [5 x i8] c"main\00", align 1
+
+define void @main.init() {
+_llgo_0:
+  %0 = load i1, ptr @"main.init$guard", align 1
+  br i1 %0, label %_llgo_2, label %_llgo_1
+
+_llgo_1:                                          ; preds = %_llgo_0
+  store i1 true, ptr @"main.init$guard", align 1
+  call void @"github.com/goplus/llgo/cl/internal/foo.init"()
+  call void @"main.init$abi"()
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  ret void
+}
+
+define i32 @main(i32 %0, ptr %1) {
+_llgo_0:
+  store i32 %0, ptr @__llgo_argc, align 4
+  store ptr %1, ptr @__llgo_argv, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.init"()
+  call void @main.init()
+  %2 = call %"github.com/goplus/llgo/internal/runtime.eface" @"github.com/goplus/llgo/cl/internal/foo.Bar"()
+  %3 = alloca { i64 }, align 8
+  %4 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %3, i64 8)
+  %5 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %2, 0
+  %6 = load ptr, ptr @"_llgo_struct$K-dZ9QotZfVPz2a0YdRa9vmZUuDXPTqZOlMShKEDJtk", align 8
+  %7 = icmp eq ptr %5, %6
+  %8 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %2, 1
+  %9 = ptrtoint ptr %8 to i64
+  %10 = alloca { i64 }, align 8
+  %11 = getelementptr inbounds { i64 }, ptr %10, i32 0, i32 0
+  store i64 %9, ptr %11, align 4
+  %12 = load { i64 }, ptr %10, align 4
+  %13 = alloca { { i64 }, i1 }, align 8
+  %14 = getelementptr inbounds { { i64 }, i1 }, ptr %13, i32 0, i32 0
+  store { i64 } %12, ptr %14, align 4
+  %15 = getelementptr inbounds { { i64 }, i1 }, ptr %13, i32 0, i32 1
+  store i1 true, ptr %15, align 1
+  %16 = load { { i64 }, i1 }, ptr %13, align 4
+  %17 = alloca { { i64 }, i1 }, align 8
+  %18 = getelementptr inbounds { { i64 }, i1 }, ptr %17, i32 0, i32 0
+  store { i64 } zeroinitializer, ptr %18, align 4
+  %19 = getelementptr inbounds { { i64 }, i1 }, ptr %17, i32 0, i32 1
+  store i1 false, ptr %19, align 1
+  %20 = load { { i64 }, i1 }, ptr %17, align 4
+  %21 = select i1 %7, { { i64 }, i1 } %16, { { i64 }, i1 } %20
+  %22 = extractvalue { { i64 }, i1 } %21, 0
+  store { i64 } %22, ptr %4, align 4
+  %23 = extractvalue { { i64 }, i1 } %21, 1
+  br i1 %23, label %_llgo_1, label %_llgo_3
+
+_llgo_1:                                          ; preds = %_llgo_0
+  %24 = getelementptr inbounds { i64 }, ptr %4, i32 0, i32 0
+  %25 = load i64, ptr %24, align 4
+  %26 = call i32 (ptr, ...) @printf(ptr @0, i64 %25)
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_3, %_llgo_1
+  %27 = alloca { i64 }, align 8
+  %28 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %27, i64 8)
+  %29 = call %"github.com/goplus/llgo/internal/runtime.eface" @"github.com/goplus/llgo/cl/internal/foo.F"()
+  %30 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %29, 0
+  %31 = load ptr, ptr @"main.struct$MYpsoM99ZwFY087IpUOkIw1zjBA_sgFXVodmn1m-G88", align 8
+  %32 = icmp eq ptr %30, %31
+  %33 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %29, 1
+  %34 = ptrtoint ptr %33 to i64
+  %35 = alloca { i64 }, align 8
+  %36 = getelementptr inbounds { i64 }, ptr %35, i32 0, i32 0
+  store i64 %34, ptr %36, align 4
+  %37 = load { i64 }, ptr %35, align 4
+  %38 = alloca { { i64 }, i1 }, align 8
+  %39 = getelementptr inbounds { { i64 }, i1 }, ptr %38, i32 0, i32 0
+  store { i64 } %37, ptr %39, align 4
+  %40 = getelementptr inbounds { { i64 }, i1 }, ptr %38, i32 0, i32 1
+  store i1 true, ptr %40, align 1
+  %41 = load { { i64 }, i1 }, ptr %38, align 4
+  %42 = alloca { { i64 }, i1 }, align 8
+  %43 = getelementptr inbounds { { i64 }, i1 }, ptr %42, i32 0, i32 0
+  store { i64 } zeroinitializer, ptr %43, align 4
+  %44 = getelementptr inbounds { { i64 }, i1 }, ptr %42, i32 0, i32 1
+  store i1 false, ptr %44, align 1
+  %45 = load { { i64 }, i1 }, ptr %42, align 4
+  %46 = select i1 %32, { { i64 }, i1 } %41, { { i64 }, i1 } %45
+  %47 = extractvalue { { i64 }, i1 } %46, 0
+  store { i64 } %47, ptr %28, align 4
+  %48 = extractvalue { { i64 }, i1 } %46, 1
+  br i1 %48, label %_llgo_4, label %_llgo_6
+
+_llgo_3:                                          ; preds = %_llgo_0
+  %49 = call i32 (ptr, ...) @printf(ptr @1)
+  br label %_llgo_2
+
+_llgo_4:                                          ; preds = %_llgo_2
+  %50 = getelementptr inbounds { i64 }, ptr %28, i32 0, i32 0
+  %51 = load i64, ptr %50, align 4
+  %52 = call i32 (ptr, ...) @printf(ptr @2, i64 %51)
+  br label %_llgo_5
+
+_llgo_5:                                          ; preds = %_llgo_6, %_llgo_4
+  ret i32 0
+
+_llgo_6:                                          ; preds = %_llgo_2
+  %53 = call i32 (ptr, ...) @printf(ptr @3)
+  br label %_llgo_5
+}
+
+declare void @"github.com/goplus/llgo/cl/internal/foo.init"()
+
+declare void @"github.com/goplus/llgo/internal/runtime.init"()
+
+declare %"github.com/goplus/llgo/internal/runtime.eface" @"github.com/goplus/llgo/cl/internal/foo.Bar"()
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr, i64)
+
+declare i32 @printf(ptr, ...)
+
+declare %"github.com/goplus/llgo/internal/runtime.eface" @"github.com/goplus/llgo/cl/internal/foo.F"()
+
+define void @"main.init$abi"() {
+_llgo_0:
+  %0 = load ptr, ptr @"_llgo_struct$K-dZ9QotZfVPz2a0YdRa9vmZUuDXPTqZOlMShKEDJtk", align 8
+  %1 = icmp eq ptr %0, null
+  br i1 %1, label %_llgo_1, label %_llgo_2
+
+_llgo_1:                                          ; preds = %_llgo_0
+  %2 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 0
+  store ptr @4, ptr %3, align 8
+  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 1
+  store i64 1, ptr %4, align 4
+  %5 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %2, align 8
+  %6 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
+  %7 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %8 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %7, i32 0, i32 0
+  store ptr @5, ptr %8, align 8
+  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %7, i32 0, i32 1
+  store i64 0, ptr %9, align 4
+  %10 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %7, align 8
+  %11 = call %"github.com/goplus/llgo/internal/abi.StructField" @"github.com/goplus/llgo/internal/runtime.StructField"(%"github.com/goplus/llgo/internal/runtime.String" %5, ptr %6, i64 0, %"github.com/goplus/llgo/internal/runtime.String" %10, i1 true, i1 false)
+  %12 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %13 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %12, i32 0, i32 0
+  store ptr @6, ptr %13, align 8
+  %14 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %12, i32 0, i32 1
+  store i64 4, ptr %14, align 4
+  %15 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %12, align 8
+  %16 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 24)
+  %17 = getelementptr %"github.com/goplus/llgo/internal/abi.StructField", ptr %16, i64 0
+  store %"github.com/goplus/llgo/internal/abi.StructField" %11, ptr %17, align 8
+  %18 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %19 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %18, i32 0, i32 0
+  store ptr %16, ptr %19, align 8
+  %20 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %18, i32 0, i32 1
+  store i64 1, ptr %20, align 4
+  %21 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %18, i32 0, i32 2
+  store i64 1, ptr %21, align 4
+  %22 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %18, align 8
+  %23 = call ptr @"github.com/goplus/llgo/internal/runtime.Struct"(%"github.com/goplus/llgo/internal/runtime.String" %15, %"github.com/goplus/llgo/internal/runtime.Slice" %22)
+  store ptr %23, ptr @"_llgo_struct$K-dZ9QotZfVPz2a0YdRa9vmZUuDXPTqZOlMShKEDJtk", align 8
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  %24 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %25 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %24, i32 0, i32 0
+  store ptr @7, ptr %25, align 8
+  %26 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %24, i32 0, i32 1
+  store i64 1, ptr %26, align 4
+  %27 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %24, align 8
+  %28 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
+  %29 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %30 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %29, i32 0, i32 0
+  store ptr @8, ptr %30, align 8
+  %31 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %29, i32 0, i32 1
+  store i64 0, ptr %31, align 4
+  %32 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %29, align 8
+  %33 = call %"github.com/goplus/llgo/internal/abi.StructField" @"github.com/goplus/llgo/internal/runtime.StructField"(%"github.com/goplus/llgo/internal/runtime.String" %27, ptr %28, i64 0, %"github.com/goplus/llgo/internal/runtime.String" %32, i1 false, i1 false)
+  %34 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %35 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %34, i32 0, i32 0
+  store ptr @9, ptr %35, align 8
+  %36 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %34, i32 0, i32 1
+  store i64 4, ptr %36, align 4
+  %37 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %34, align 8
+  %38 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 24)
+  %39 = getelementptr %"github.com/goplus/llgo/internal/abi.StructField", ptr %38, i64 0
+  store %"github.com/goplus/llgo/internal/abi.StructField" %33, ptr %39, align 8
+  %40 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %41 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %40, i32 0, i32 0
+  store ptr %38, ptr %41, align 8
+  %42 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %40, i32 0, i32 1
+  store i64 1, ptr %42, align 4
+  %43 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %40, i32 0, i32 2
+  store i64 1, ptr %43, align 4
+  %44 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %40, align 8
+  %45 = call ptr @"github.com/goplus/llgo/internal/runtime.Struct"(%"github.com/goplus/llgo/internal/runtime.String" %37, %"github.com/goplus/llgo/internal/runtime.Slice" %44)
+  store ptr %45, ptr @"main.struct$MYpsoM99ZwFY087IpUOkIw1zjBA_sgFXVodmn1m-G88", align 8
+  ret void
+}
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.Struct"(i64, %"github.com/goplus/llgo/internal/runtime.String", %"github.com/goplus/llgo/internal/runtime.Slice")
+
+declare %"github.com/goplus/llgo/internal/abi.StructField" @"github.com/goplus/llgo/internal/runtime.StructField"(%"github.com/goplus/llgo/internal/runtime.String", ptr, i64, %"github.com/goplus/llgo/internal/runtime.String", i1, i1)
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64)
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64)
diff --git a/cl/_testrt/gotypes/in.go b/cl/_testrt/_gotypes/in.go
similarity index 100%
rename from cl/_testrt/gotypes/in.go
rename to cl/_testrt/_gotypes/in.go
diff --git a/cl/_testrt/gotypes/out.ll b/cl/_testrt/_gotypes/out.ll
similarity index 100%
rename from cl/_testrt/gotypes/out.ll
rename to cl/_testrt/_gotypes/out.ll
diff --git a/cl/_testrt/any/out.ll b/cl/_testrt/any/out.ll
index fbf58289..207fc6d3 100644
--- a/cl/_testrt/any/out.ll
+++ b/cl/_testrt/any/out.ll
@@ -1,19 +1,37 @@
 ; ModuleID = 'main'
 source_filename = "main"
 
-%"github.com/goplus/llgo/internal/runtime.iface" = type { ptr, ptr }
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
+%"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
 
 @"main.init$guard" = global ptr null
+@0 = private unnamed_addr constant [22 x i8] c"type assertion failed\00", align 1
 @__llgo_argc = global ptr null
 @__llgo_argv = global ptr null
-@0 = private unnamed_addr constant [10 x i8] c"Hello %d\0A\00", align 1
+@1 = private unnamed_addr constant [10 x i8] c"Hello %d\0A\00", align 1
 
-define i64 @main.incVal(%"github.com/goplus/llgo/internal/runtime.iface" %0) {
+define i64 @main.incVal(%"github.com/goplus/llgo/internal/runtime.eface" %0) {
 _llgo_0:
-  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
-  %2 = call i64 @"github.com/goplus/llgo/internal/runtime.I2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %1)
-  %3 = add i64 %2, 1
-  ret i64 %3
+  %1 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 0
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
+  %3 = icmp eq ptr %1, %2
+  br i1 %3, label %_llgo_1, label %_llgo_2
+
+_llgo_1:                                          ; preds = %_llgo_0
+  %4 = extractvalue %"github.com/goplus/llgo/internal/runtime.eface" %0, 1
+  %5 = ptrtoint ptr %4 to i64
+  %6 = add i64 %5, 1
+  ret i64 %6
+
+_llgo_2:                                          ; preds = %_llgo_0
+  %7 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %8 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %7, i32 0, i32 0
+  store ptr @0, ptr %8, align 8
+  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %7, i32 0, i32 1
+  store i64 21, ptr %9, align 4
+  %10 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %7, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.String" %10)
+  unreachable
 }
 
 define void @main.init() {
@@ -36,18 +54,21 @@ _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
   %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
-  %3 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %2, i64 100)
-  %4 = call i64 @main.incVal(%"github.com/goplus/llgo/internal/runtime.iface" %3)
-  %5 = call i32 (ptr, ...) @printf(ptr @0, i64 %4)
+  %3 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %3, i32 0, i32 0
+  store ptr %2, ptr %4, align 8
+  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %3, i32 0, i32 1
+  store ptr inttoptr (i64 100 to ptr), ptr %5, align 8
+  %6 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %3, align 8
+  %7 = call i64 @main.incVal(%"github.com/goplus/llgo/internal/runtime.eface" %6)
+  %8 = call i32 (ptr, ...) @printf(ptr @1, i64 %7)
   ret i32 0
 }
 
-declare i64 @"github.com/goplus/llgo/internal/runtime.I2Int"(%"github.com/goplus/llgo/internal/runtime.iface", ptr)
-
 declare ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64)
 
+declare void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface")
+
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
-declare %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr, i64)
-
 declare i32 @printf(ptr, ...)
diff --git a/cl/_testrt/builtin/out.ll b/cl/_testrt/builtin/out.ll
index c921f898..d6c806f3 100644
--- a/cl/_testrt/builtin/out.ll
+++ b/cl/_testrt/builtin/out.ll
@@ -3,7 +3,7 @@ source_filename = "main"
 
 %"github.com/goplus/llgo/internal/runtime.Slice" = type { ptr, i64, i64 }
 %"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
-%"github.com/goplus/llgo/internal/runtime.iface" = type { ptr, ptr }
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
 
 @main.a = global ptr null
 @main.b = global ptr null
@@ -55,33 +55,40 @@ _llgo_0:
   store i64 3, ptr %5, align 4
   %6 = getelementptr inbounds i64, ptr %2, i64 3
   store i64 4, ptr %6, align 4
-  %7 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %2, i64 8, i64 4, i64 0, i64 4, i64 4)
-  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
-  %9 = getelementptr inbounds i64, ptr %8, i64 0
-  %10 = getelementptr inbounds i64, ptr %8, i64 1
-  %11 = getelementptr inbounds i64, ptr %8, i64 2
-  %12 = getelementptr inbounds i64, ptr %8, i64 3
-  store i64 1, ptr %9, align 4
-  store i64 2, ptr %10, align 4
-  store i64 3, ptr %11, align 4
-  store i64 4, ptr %12, align 4
-  %13 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 10)
-  %14 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %13, i64 1, i64 10, i64 0, i64 4, i64 10)
-  %15 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 1
-  %16 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 2
-  call void @"github.com/goplus/llgo/internal/runtime.PrintSlice"(%"github.com/goplus/llgo/internal/runtime.Slice" %7)
+  %7 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %8 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, i32 0, i32 0
+  store ptr %2, ptr %8, align 8
+  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, i32 0, i32 1
+  store i64 4, ptr %9, align 4
+  %10 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, i32 0, i32 2
+  store i64 4, ptr %10, align 4
+  %11 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, align 8
+  %12 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
+  %13 = getelementptr inbounds i64, ptr %12, i64 0
+  %14 = getelementptr inbounds i64, ptr %12, i64 1
+  %15 = getelementptr inbounds i64, ptr %12, i64 2
+  %16 = getelementptr inbounds i64, ptr %12, i64 3
+  store i64 1, ptr %13, align 4
+  store i64 2, ptr %14, align 4
+  store i64 3, ptr %15, align 4
+  store i64 4, ptr %16, align 4
+  %17 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 10)
+  %18 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %17, i64 1, i64 10, i64 0, i64 4, i64 10)
+  %19 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 1
+  %20 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 2
+  call void @"github.com/goplus/llgo/internal/runtime.PrintSlice"(%"github.com/goplus/llgo/internal/runtime.Slice" %11)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %15)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %19)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %16)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %20)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
-  %17 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %14, 1
-  %18 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %14, 2
-  call void @"github.com/goplus/llgo/internal/runtime.PrintSlice"(%"github.com/goplus/llgo/internal/runtime.Slice" %14)
+  %21 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %18, 1
+  %22 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %18, 2
+  call void @"github.com/goplus/llgo/internal/runtime.PrintSlice"(%"github.com/goplus/llgo/internal/runtime.Slice" %18)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %17)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %21)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %18)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %22)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 4)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
@@ -91,161 +98,187 @@ _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 4)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
-  %19 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
-  %20 = getelementptr inbounds i64, ptr %19, i64 0
-  store i64 1, ptr %20, align 4
-  %21 = getelementptr inbounds i64, ptr %19, i64 1
-  store i64 2, ptr %21, align 4
-  %22 = getelementptr inbounds i64, ptr %19, i64 2
-  store i64 3, ptr %22, align 4
-  %23 = getelementptr inbounds i64, ptr %19, i64 3
-  store i64 4, ptr %23, align 4
-  %24 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %19, i64 8, i64 4, i64 0, i64 4, i64 4)
-  %25 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %24, 1
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %25)
+  %23 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
+  %24 = getelementptr inbounds i64, ptr %23, i64 0
+  store i64 1, ptr %24, align 4
+  %25 = getelementptr inbounds i64, ptr %23, i64 1
+  store i64 2, ptr %25, align 4
+  %26 = getelementptr inbounds i64, ptr %23, i64 2
+  store i64 3, ptr %26, align 4
+  %27 = getelementptr inbounds i64, ptr %23, i64 3
+  store i64 4, ptr %27, align 4
+  %28 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %29 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %28, i32 0, i32 0
+  store ptr %23, ptr %29, align 8
+  %30 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %28, i32 0, i32 1
+  store i64 4, ptr %30, align 4
+  %31 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %28, i32 0, i32 2
+  store i64 4, ptr %31, align 4
+  %32 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %28, align 8
+  %33 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %32, 1
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %33)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 4)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
-  %26 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 2
-  %27 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 2
-  %28 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 0
-  %29 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %28, i64 8, i64 %26, i64 1, i64 %27, i64 %26)
-  %30 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %29, 1
-  %31 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 2
-  %32 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 2
-  %33 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 0
-  %34 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %33, i64 8, i64 %31, i64 1, i64 %32, i64 %31)
-  %35 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %34, 2
-  %36 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 2
-  %37 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 0
-  %38 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %37, i64 8, i64 %36, i64 1, i64 2, i64 %36)
-  %39 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %38, 1
-  %40 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 2
-  %41 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 0
-  %42 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %41, i64 8, i64 %40, i64 1, i64 2, i64 %40)
+  %34 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 2
+  %35 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 2
+  %36 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 0
+  %37 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %36, i64 32, i64 %34, i64 1, i64 %35, i64 %34)
+  %38 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %37, 1
+  %39 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 2
+  %40 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 2
+  %41 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 0
+  %42 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %41, i64 32, i64 %39, i64 1, i64 %40, i64 %39)
   %43 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %42, 2
-  %44 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 2
-  %45 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 0
-  %46 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %45, i64 8, i64 %44, i64 1, i64 2, i64 2)
+  %44 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 2
+  %45 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 0
+  %46 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %45, i64 32, i64 %44, i64 1, i64 2, i64 %44)
   %47 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %46, 1
-  %48 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 2
-  %49 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %7, 0
-  %50 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %49, i64 8, i64 %48, i64 1, i64 2, i64 2)
+  %48 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 2
+  %49 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 0
+  %50 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %49, i64 32, i64 %48, i64 1, i64 2, i64 %48)
   %51 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %50, 2
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %30)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %35)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %39)
+  %52 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 2
+  %53 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 0
+  %54 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %53, i64 32, i64 %52, i64 1, i64 2, i64 2)
+  %55 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %54, 1
+  %56 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 2
+  %57 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %11, 0
+  %58 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %57, i64 32, i64 %56, i64 1, i64 2, i64 2)
+  %59 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %58, 2
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %38)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %43)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %47)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %51)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
-  %52 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %8, i64 8, i64 4, i64 1, i64 4, i64 4)
-  %53 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %52, 1
-  %54 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %8, i64 8, i64 4, i64 1, i64 4, i64 4)
-  %55 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %54, 2
-  %56 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %8, i64 8, i64 4, i64 1, i64 2, i64 4)
-  %57 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %56, 1
-  %58 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %8, i64 8, i64 4, i64 1, i64 2, i64 4)
-  %59 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %58, 2
-  %60 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %8, i64 8, i64 4, i64 1, i64 2, i64 2)
-  %61 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %60, 1
-  %62 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %8, i64 8, i64 4, i64 1, i64 2, i64 2)
-  %63 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %62, 2
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %53)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %55)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %57)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %59)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
+  %60 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %12, i64 8, i64 4, i64 1, i64 4, i64 4)
+  %61 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %60, 1
+  %62 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %12, i64 8, i64 4, i64 1, i64 4, i64 4)
+  %63 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %62, 2
+  %64 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %12, i64 8, i64 4, i64 1, i64 2, i64 4)
+  %65 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %64, 1
+  %66 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %12, i64 8, i64 4, i64 1, i64 2, i64 4)
+  %67 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %66, 2
+  %68 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %12, i64 8, i64 4, i64 1, i64 2, i64 2)
+  %69 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %68, 1
+  %70 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %12, i64 8, i64 4, i64 1, i64 2, i64 2)
+  %71 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %70, 2
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %61)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %63)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
-  %64 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %65 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %64, i32 0, i32 0
-  store ptr @0, ptr %65, align 8
-  %66 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %64, i32 0, i32 1
-  store i64 5, ptr %66, align 4
-  %67 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %64, align 8
-  %68 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %67, 1
-  %69 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewStringSlice"(%"github.com/goplus/llgo/internal/runtime.String" %67, i64 1, i64 %68)
-  %70 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %71 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %70, i32 0, i32 0
-  store ptr @1, ptr %71, align 8
-  %72 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %70, i32 0, i32 1
-  store i64 5, ptr %72, align 4
-  %73 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %70, align 8
-  %74 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewStringSlice"(%"github.com/goplus/llgo/internal/runtime.String" %73, i64 1, i64 2)
-  %75 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %76 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %75, i32 0, i32 0
-  store ptr @2, ptr %76, align 8
-  %77 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %75, i32 0, i32 1
-  store i64 5, ptr %77, align 4
-  %78 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %75, align 8
-  %79 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %78, 1
-  %80 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewStringSlice"(%"github.com/goplus/llgo/internal/runtime.String" %78, i64 5, i64 %79)
-  %81 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %80, 1
-  %82 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %83 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %82, i32 0, i32 0
-  store ptr @3, ptr %83, align 8
-  %84 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %82, i32 0, i32 1
-  store i64 5, ptr %84, align 4
-  %85 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %82, align 8
-  call void @"github.com/goplus/llgo/internal/runtime.PrintString"(%"github.com/goplus/llgo/internal/runtime.String" %85)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintString"(%"github.com/goplus/llgo/internal/runtime.String" %69)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %65)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintString"(%"github.com/goplus/llgo/internal/runtime.String" %74)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %67)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %81)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %69)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %71)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
-  %86 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
-  %87 = getelementptr inbounds i64, ptr %86, i64 0
-  store i64 5, ptr %87, align 4
-  %88 = getelementptr inbounds i64, ptr %86, i64 1
-  store i64 6, ptr %88, align 4
-  %89 = getelementptr inbounds i64, ptr %86, i64 2
-  store i64 7, ptr %89, align 4
-  %90 = getelementptr inbounds i64, ptr %86, i64 3
-  store i64 8, ptr %90, align 4
-  %91 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %86, i64 8, i64 4, i64 0, i64 4, i64 4)
-  %92 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %91, 0
-  %93 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %91, 1
-  %94 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.SliceAppend"(%"github.com/goplus/llgo/internal/runtime.Slice" %7, ptr %92, i64 %93, i64 8)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintSlice"(%"github.com/goplus/llgo/internal/runtime.Slice" %94)
+  %72 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %73 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %72, i32 0, i32 0
+  store ptr @0, ptr %73, align 8
+  %74 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %72, i32 0, i32 1
+  store i64 5, ptr %74, align 4
+  %75 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %72, align 8
+  %76 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %75, 1
+  %77 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewStringSlice"(%"github.com/goplus/llgo/internal/runtime.String" %75, i64 1, i64 %76)
+  %78 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %79 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %78, i32 0, i32 0
+  store ptr @1, ptr %79, align 8
+  %80 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %78, i32 0, i32 1
+  store i64 5, ptr %80, align 4
+  %81 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %78, align 8
+  %82 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewStringSlice"(%"github.com/goplus/llgo/internal/runtime.String" %81, i64 1, i64 2)
+  %83 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %84 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %83, i32 0, i32 0
+  store ptr @2, ptr %84, align 8
+  %85 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %83, i32 0, i32 1
+  store i64 5, ptr %85, align 4
+  %86 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %83, align 8
+  %87 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %86, 1
+  %88 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewStringSlice"(%"github.com/goplus/llgo/internal/runtime.String" %86, i64 5, i64 %87)
+  %89 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %88, 1
+  %90 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %91 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %90, i32 0, i32 0
+  store ptr @3, ptr %91, align 8
+  %92 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %90, i32 0, i32 1
+  store i64 5, ptr %92, align 4
+  %93 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %90, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.PrintString"(%"github.com/goplus/llgo/internal/runtime.String" %93)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintString"(%"github.com/goplus/llgo/internal/runtime.String" %77)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintString"(%"github.com/goplus/llgo/internal/runtime.String" %82)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %89)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
-  %95 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 3)
-  %96 = getelementptr inbounds i8, ptr %95, i64 0
-  store i8 97, ptr %96, align 1
-  %97 = getelementptr inbounds i8, ptr %95, i64 1
-  store i8 98, ptr %97, align 1
-  %98 = getelementptr inbounds i8, ptr %95, i64 2
-  store i8 99, ptr %98, align 1
-  %99 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %95, i64 1, i64 3, i64 0, i64 3, i64 3)
-  %100 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %101 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %100, i32 0, i32 0
-  store ptr @4, ptr %101, align 8
-  %102 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %100, i32 0, i32 1
-  store i64 3, ptr %102, align 4
-  %103 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %100, align 8
-  %104 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %103, 0
-  %105 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %103, 1
-  %106 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.SliceAppend"(%"github.com/goplus/llgo/internal/runtime.Slice" %99, ptr %104, i64 %105, i64 1)
+  %94 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
+  %95 = getelementptr inbounds i64, ptr %94, i64 0
+  store i64 5, ptr %95, align 4
+  %96 = getelementptr inbounds i64, ptr %94, i64 1
+  store i64 6, ptr %96, align 4
+  %97 = getelementptr inbounds i64, ptr %94, i64 2
+  store i64 7, ptr %97, align 4
+  %98 = getelementptr inbounds i64, ptr %94, i64 3
+  store i64 8, ptr %98, align 4
+  %99 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %100 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %99, i32 0, i32 0
+  store ptr %94, ptr %100, align 8
+  %101 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %99, i32 0, i32 1
+  store i64 4, ptr %101, align 4
+  %102 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %99, i32 0, i32 2
+  store i64 4, ptr %102, align 4
+  %103 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %99, align 8
+  %104 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %103, 0
+  %105 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %103, 1
+  %106 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.SliceAppend"(%"github.com/goplus/llgo/internal/runtime.Slice" %11, ptr %104, i64 %105, i64 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintSlice"(%"github.com/goplus/llgo/internal/runtime.Slice" %106)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
-  %107 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 16)
-  %108 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
-  %109 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr %108, i64 100)
-  store %"github.com/goplus/llgo/internal/runtime.iface" %109, ptr %107, align 8
-  %110 = load %"github.com/goplus/llgo/internal/runtime.iface", ptr %107, align 8
-  %111 = ptrtoint ptr %107 to i64
+  %107 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 3)
+  %108 = getelementptr inbounds i8, ptr %107, i64 0
+  store i8 97, ptr %108, align 1
+  %109 = getelementptr inbounds i8, ptr %107, i64 1
+  store i8 98, ptr %109, align 1
+  %110 = getelementptr inbounds i8, ptr %107, i64 2
+  store i8 99, ptr %110, align 1
+  %111 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %112 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %111, i32 0, i32 0
+  store ptr %107, ptr %112, align 8
+  %113 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %111, i32 0, i32 1
+  store i64 3, ptr %113, align 4
+  %114 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %111, i32 0, i32 2
+  store i64 3, ptr %114, align 4
+  %115 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %111, align 8
+  %116 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %117 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %116, i32 0, i32 0
+  store ptr @4, ptr %117, align 8
+  %118 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %116, i32 0, i32 1
+  store i64 3, ptr %118, align 4
+  %119 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %116, align 8
+  %120 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %119, 0
+  %121 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %119, 1
+  %122 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.SliceAppend"(%"github.com/goplus/llgo/internal/runtime.Slice" %115, ptr %120, i64 %121, i64 1)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintSlice"(%"github.com/goplus/llgo/internal/runtime.Slice" %122)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
+  %123 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 16)
+  %124 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
+  %125 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %126 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %125, i32 0, i32 0
+  store ptr %124, ptr %126, align 8
+  %127 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %125, i32 0, i32 1
+  store ptr inttoptr (i64 100 to ptr), ptr %127, align 8
+  %128 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %125, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %128, ptr %123, align 8
+  %129 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %123, align 8
+  %130 = ptrtoint ptr %123 to i64
   call void @"github.com/goplus/llgo/internal/runtime.PrintBool"(i1 true)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 0)
@@ -262,83 +295,90 @@ _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintFloat"(double 1.005000e+02)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintIface"(%"github.com/goplus/llgo/internal/runtime.iface" %110)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintEface"(%"github.com/goplus/llgo/internal/runtime.eface" %129)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintPointer"(ptr %107)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintPointer"(ptr %123)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %111)
+  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %130)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
-  %112 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 3)
-  %113 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 8)
-  %114 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %112, i64 1, i64 3, i64 0, i64 3, i64 3)
-  %115 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %106, 0
-  %116 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %106, 1
-  %117 = call i64 @"github.com/goplus/llgo/internal/runtime.SliceCopy"(%"github.com/goplus/llgo/internal/runtime.Slice" %114, ptr %115, i64 %116, i64 1)
-  store i64 %117, ptr %113, align 4
-  %118 = load i64, ptr %113, align 4
-  %119 = getelementptr inbounds i8, ptr %112, i64 0
-  %120 = load i8, ptr %119, align 1
-  %121 = getelementptr inbounds i8, ptr %112, i64 1
-  %122 = load i8, ptr %121, align 1
-  %123 = getelementptr inbounds i8, ptr %112, i64 2
-  %124 = load i8, ptr %123, align 1
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %118)
+  %131 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 3)
+  %132 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 8)
+  %133 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %134 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %133, i32 0, i32 0
+  store ptr %131, ptr %134, align 8
+  %135 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %133, i32 0, i32 1
+  store i64 3, ptr %135, align 4
+  %136 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %133, i32 0, i32 2
+  store i64 3, ptr %136, align 4
+  %137 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %133, align 8
+  %138 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %122, 0
+  %139 = extractvalue %"github.com/goplus/llgo/internal/runtime.Slice" %122, 1
+  %140 = call i64 @"github.com/goplus/llgo/internal/runtime.SliceCopy"(%"github.com/goplus/llgo/internal/runtime.Slice" %137, ptr %138, i64 %139, i64 3)
+  store i64 %140, ptr %132, align 4
+  %141 = load i64, ptr %132, align 4
+  %142 = getelementptr inbounds i8, ptr %131, i64 0
+  %143 = load i8, ptr %142, align 1
+  %144 = getelementptr inbounds i8, ptr %131, i64 1
+  %145 = load i8, ptr %144, align 1
+  %146 = getelementptr inbounds i8, ptr %131, i64 2
+  %147 = load i8, ptr %146, align 1
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %141)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  %125 = zext i8 %120 to i64
-  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %125)
+  %148 = zext i8 %143 to i64
+  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %148)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  %126 = zext i8 %122 to i64
-  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %126)
+  %149 = zext i8 %145 to i64
+  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %149)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  %127 = zext i8 %124 to i64
-  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %127)
+  %150 = zext i8 %147 to i64
+  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %150)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
-  %128 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %112, i64 1, i64 3, i64 1, i64 3, i64 3)
-  %129 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %130 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %129, i32 0, i32 0
-  store ptr @5, ptr %130, align 8
-  %131 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %129, i32 0, i32 1
-  store i64 4, ptr %131, align 4
-  %132 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %129, align 8
-  %133 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %132, 0
-  %134 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %132, 1
-  %135 = call i64 @"github.com/goplus/llgo/internal/runtime.SliceCopy"(%"github.com/goplus/llgo/internal/runtime.Slice" %128, ptr %133, i64 %134, i64 1)
-  store i64 %135, ptr %113, align 4
-  %136 = load i64, ptr %113, align 4
-  %137 = getelementptr inbounds i8, ptr %112, i64 0
-  %138 = load i8, ptr %137, align 1
-  %139 = getelementptr inbounds i8, ptr %112, i64 1
-  %140 = load i8, ptr %139, align 1
-  %141 = getelementptr inbounds i8, ptr %112, i64 2
-  %142 = load i8, ptr %141, align 1
-  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %136)
+  %151 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %131, i64 1, i64 3, i64 1, i64 3, i64 3)
+  %152 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %153 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %152, i32 0, i32 0
+  store ptr @5, ptr %153, align 8
+  %154 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %152, i32 0, i32 1
+  store i64 4, ptr %154, align 4
+  %155 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %152, align 8
+  %156 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %155, 0
+  %157 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %155, 1
+  %158 = call i64 @"github.com/goplus/llgo/internal/runtime.SliceCopy"(%"github.com/goplus/llgo/internal/runtime.Slice" %151, ptr %156, i64 %157, i64 1)
+  store i64 %158, ptr %132, align 4
+  %159 = load i64, ptr %132, align 4
+  %160 = getelementptr inbounds i8, ptr %131, i64 0
+  %161 = load i8, ptr %160, align 1
+  %162 = getelementptr inbounds i8, ptr %131, i64 1
+  %163 = load i8, ptr %162, align 1
+  %164 = getelementptr inbounds i8, ptr %131, i64 2
+  %165 = load i8, ptr %164, align 1
+  call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %159)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  %143 = zext i8 %138 to i64
-  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %143)
+  %166 = zext i8 %161 to i64
+  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %166)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  %144 = zext i8 %140 to i64
-  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %144)
+  %167 = zext i8 %163 to i64
+  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %167)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  %145 = zext i8 %142 to i64
-  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %145)
+  %168 = zext i8 %165 to i64
+  call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %168)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
-  %146 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 8)
-  %147 = getelementptr inbounds { ptr }, ptr %146, i32 0, i32 0
-  store ptr %113, ptr %147, align 8
-  %148 = alloca { ptr, ptr }, align 8
-  %149 = getelementptr inbounds { ptr, ptr }, ptr %148, i32 0, i32 0
-  store ptr @"main.main$2", ptr %149, align 8
-  %150 = getelementptr inbounds { ptr, ptr }, ptr %148, i32 0, i32 1
-  store ptr %146, ptr %150, align 8
-  %151 = load { ptr, ptr }, ptr %148, align 8
+  %169 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 8)
+  %170 = getelementptr inbounds { ptr }, ptr %169, i32 0, i32 0
+  store ptr %132, ptr %170, align 8
+  %171 = alloca { ptr, ptr }, align 8
+  %172 = getelementptr inbounds { ptr, ptr }, ptr %171, i32 0, i32 0
+  store ptr @"main.main$2", ptr %172, align 8
+  %173 = getelementptr inbounds { ptr, ptr }, ptr %171, i32 0, i32 1
+  store ptr %169, ptr %173, align 8
+  %174 = load { ptr, ptr }, ptr %171, align 8
   call void @"github.com/goplus/llgo/internal/runtime.PrintPointer"(ptr @main.demo)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintPointer"(ptr @main.demo)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
   call void @"github.com/goplus/llgo/internal/runtime.PrintPointer"(ptr @"main.main$1")
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 32)
-  %152 = extractvalue { ptr, ptr } %151, 0
-  call void @"github.com/goplus/llgo/internal/runtime.PrintPointer"(ptr %152)
+  %175 = extractvalue { ptr, ptr } %174, 0
+  call void @"github.com/goplus/llgo/internal/runtime.PrintPointer"(ptr %175)
   call void @"github.com/goplus/llgo/internal/runtime.PrintByte"(i8 10)
   ret i32 0
 }
@@ -361,8 +401,6 @@ declare void @"github.com/goplus/llgo/internal/runtime.PrintString"(%"github.com
 
 declare %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.SliceAppend"(%"github.com/goplus/llgo/internal/runtime.Slice", ptr, i64, i64)
 
-declare %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyIntptr"(ptr, i64)
-
 declare ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64)
 
 declare void @"github.com/goplus/llgo/internal/runtime.PrintBool"(i1)
@@ -371,7 +409,7 @@ declare void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64)
 
 declare void @"github.com/goplus/llgo/internal/runtime.PrintFloat"(double)
 
-declare void @"github.com/goplus/llgo/internal/runtime.PrintIface"(%"github.com/goplus/llgo/internal/runtime.iface")
+declare void @"github.com/goplus/llgo/internal/runtime.PrintEface"(%"github.com/goplus/llgo/internal/runtime.eface")
 
 declare void @"github.com/goplus/llgo/internal/runtime.PrintPointer"(ptr)
 
diff --git a/cl/_testrt/cast/out.ll b/cl/_testrt/cast/out.ll
index b6739dbb..794eea9e 100644
--- a/cl/_testrt/cast/out.ll
+++ b/cl/_testrt/cast/out.ll
@@ -2,7 +2,7 @@
 source_filename = "main"
 
 %"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
-%"github.com/goplus/llgo/internal/runtime.iface" = type { ptr, ptr }
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
 
 @"main.init$guard" = global ptr null
 @0 = private unnamed_addr constant [6 x i8] c"error\00", align 1
@@ -34,8 +34,16 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
@@ -55,8 +63,16 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
@@ -76,8 +92,16 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
@@ -97,8 +121,16 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
@@ -118,8 +150,16 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
@@ -139,8 +179,16 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
@@ -160,8 +208,16 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
@@ -181,8 +237,16 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
@@ -202,8 +266,16 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
@@ -223,8 +295,16 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
@@ -244,8 +324,16 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
@@ -265,24 +353,40 @@ _llgo_1:                                          ; preds = %_llgo_0
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
   store i64 5, ptr %6, align 4
   %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
-  %8 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %7)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %8)
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %7, ptr %9, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 0
+  store ptr %8, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, i32 0, i32 1
+  store ptr %9, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %10, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %13)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_0
-  %9 = trunc i64 %1 to i32
-  %10 = icmp ne i32 %9, %0
-  br i1 %10, label %_llgo_3, label %_llgo_4
+  %14 = trunc i64 %1 to i32
+  %15 = icmp ne i32 %14, %0
+  br i1 %15, label %_llgo_3, label %_llgo_4
 
 _llgo_3:                                          ; preds = %_llgo_2
-  %11 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %11, i32 0, i32 0
-  store ptr @12, ptr %12, align 8
-  %13 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %11, i32 0, i32 1
-  store i64 5, ptr %13, align 4
-  %14 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %11, align 8
-  %15 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %14)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %15)
+  %16 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %17 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %16, i32 0, i32 0
+  store ptr @12, ptr %17, align 8
+  %18 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %16, i32 0, i32 1
+  store i64 5, ptr %18, align 4
+  %19 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %16, align 8
+  %20 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %21 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %19, ptr %21, align 8
+  %22 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %23 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %22, i32 0, i32 0
+  store ptr %20, ptr %23, align 8
+  %24 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %22, i32 0, i32 1
+  store ptr %21, ptr %24, align 8
+  %25 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %22, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %25)
   unreachable
 
 _llgo_4:                                          ; preds = %_llgo_2
@@ -366,8 +470,10 @@ _llgo_0:
   ret i32 0
 }
 
-declare %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String")
+declare ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64)
 
-declare void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface")
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64)
+
+declare void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface")
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/concat/out.ll b/cl/_testrt/concat/out.ll
index 845d1d0c..f850807f 100644
--- a/cl/_testrt/concat/out.ll
+++ b/cl/_testrt/concat/out.ll
@@ -121,14 +121,21 @@ _llgo_0:
   store i64 5, ptr %16, align 4
   %17 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %14, align 8
   store %"github.com/goplus/llgo/internal/runtime.String" %17, ptr %13, align 8
-  %18 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %2, i64 16, i64 3, i64 0, i64 3, i64 3)
-  %19 = call %"github.com/goplus/llgo/internal/runtime.String" @main.concat(%"github.com/goplus/llgo/internal/runtime.Slice" %18)
-  %20 = load ptr, ptr @__stderrp, align 8
-  %21 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %19, 1
-  %22 = add i64 %21, 1
-  %23 = alloca i8, i64 %22, align 1
-  %24 = call ptr @"github.com/goplus/llgo/internal/runtime.CStrCopy"(ptr %23, %"github.com/goplus/llgo/internal/runtime.String" %19)
-  %25 = call i32 (ptr, ptr, ...) @fprintf(ptr %20, ptr @6, ptr %24)
+  %18 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %19 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %18, i32 0, i32 0
+  store ptr %2, ptr %19, align 8
+  %20 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %18, i32 0, i32 1
+  store i64 3, ptr %20, align 4
+  %21 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %18, i32 0, i32 2
+  store i64 3, ptr %21, align 4
+  %22 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %18, align 8
+  %23 = call %"github.com/goplus/llgo/internal/runtime.String" @main.concat(%"github.com/goplus/llgo/internal/runtime.Slice" %22)
+  %24 = load ptr, ptr @__stderrp, align 8
+  %25 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %23, 1
+  %26 = add i64 %25, 1
+  %27 = alloca i8, i64 %26, align 1
+  %28 = call ptr @"github.com/goplus/llgo/internal/runtime.CStrCopy"(ptr %27, %"github.com/goplus/llgo/internal/runtime.String" %23)
+  %29 = call i32 (ptr, ptr, ...) @fprintf(ptr %24, ptr @6, ptr %28)
   ret i32 0
 }
 
@@ -140,8 +147,6 @@ declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
 declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
 
-declare %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr, i64, i64, i64, i64, i64)
-
 declare ptr @"github.com/goplus/llgo/internal/runtime.CStrCopy"(ptr, %"github.com/goplus/llgo/internal/runtime.String")
 
 declare i32 @fprintf(ptr, ptr, ...)
diff --git a/cl/_testrt/panic/out.ll b/cl/_testrt/panic/out.ll
index f8923d33..362b3bb2 100644
--- a/cl/_testrt/panic/out.ll
+++ b/cl/_testrt/panic/out.ll
@@ -2,7 +2,7 @@
 source_filename = "main"
 
 %"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
-%"github.com/goplus/llgo/internal/runtime.iface" = type { ptr, ptr }
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
 
 @"main.init$guard" = global ptr null
 @__llgo_argc = global ptr null
@@ -34,13 +34,23 @@ _llgo_0:
   %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 1
   store i64 13, ptr %4, align 4
   %5 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %2, align 8
-  %6 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %5)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %6)
+  %6 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  %7 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %5, ptr %7, align 8
+  %8 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %8, i32 0, i32 0
+  store ptr %6, ptr %9, align 8
+  %10 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %8, i32 0, i32 1
+  store ptr %7, ptr %10, align 8
+  %11 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %8, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface" %11)
   unreachable
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
-declare %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String")
+declare ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64)
 
-declare void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface")
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64)
+
+declare void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.eface")
diff --git a/cl/_testrt/sum/out.ll b/cl/_testrt/sum/out.ll
index e13b24a2..c36f08d1 100644
--- a/cl/_testrt/sum/out.ll
+++ b/cl/_testrt/sum/out.ll
@@ -36,9 +36,16 @@ _llgo_0:
   store i64 3, ptr %5, align 4
   %6 = getelementptr inbounds i64, ptr %2, i64 3
   store i64 4, ptr %6, align 4
-  %7 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %2, i64 8, i64 4, i64 0, i64 4, i64 4)
-  %8 = call i64 @main.sum(%"github.com/goplus/llgo/internal/runtime.Slice" %7)
-  %9 = call i32 (ptr, ...) @printf(ptr @0, i64 %8)
+  %7 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %8 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, i32 0, i32 0
+  store ptr %2, ptr %8, align 8
+  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, i32 0, i32 1
+  store i64 4, ptr %9, align 4
+  %10 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, i32 0, i32 2
+  store i64 4, ptr %10, align 4
+  %11 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, align 8
+  %12 = call i64 @main.sum(%"github.com/goplus/llgo/internal/runtime.Slice" %11)
+  %13 = call i32 (ptr, ...) @printf(ptr @0, i64 %12)
   ret i32 0
 }
 
@@ -71,8 +78,6 @@ declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
 declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
 
-declare %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr, i64, i64, i64, i64, i64)
-
 declare i32 @printf(ptr, ...)
 
 declare void @"github.com/goplus/llgo/internal/runtime.AssertIndexRange"(i1)
diff --git a/cl/compile.go b/cl/compile.go
index 6974ee81..1b23d3b8 100644
--- a/cl/compile.go
+++ b/cl/compile.go
@@ -352,9 +352,9 @@ func (p *context) compileBlock(b llssa.Builder, block *ssa.BasicBlock, n int, do
 			last = len(instrs) - 1
 			instrs = instrs[:last]
 		} else {
-			// TODO(xsw): confirm pyMod don't need to call LoadPyModSyms
+			// TODO(xsw): confirm pyMod don't need to call AfterInit
 			p.inits = append(p.inits, func() {
-				pkg.PyLoadModSyms(b, ret)
+				pkg.AfterInit(b, ret)
 			})
 		}
 	} else if doMainInit {
@@ -381,7 +381,7 @@ func (p *context) compileBlock(b llssa.Builder, block *ssa.BasicBlock, n int, do
 		cond := b.BinOp(token.NEQ, mod, prog.Null(mod.Type))
 		newBlk := p.fn.MakeBlock()
 		b.If(cond, jumpTo, newBlk)
-		b.SetBlock(newBlk)
+		b.SetBlockEx(newBlk, llssa.AtEnd, false)
 		b.Store(modPtr, b.PyImportMod(modPath))
 		b.Jump(jumpTo)
 	}
@@ -508,7 +508,7 @@ func isPhi(i ssa.Instruction) bool {
 
 func (p *context) compilePhis(b llssa.Builder, block *ssa.BasicBlock) int {
 	ret := p.fn.Block(block.Index)
-	b.SetBlockEx(ret, llssa.AtEnd)
+	b.SetBlockEx(ret, llssa.AtEnd, false)
 	if ninstr := len(block.Instrs); ninstr > 0 {
 		if isPhi(block.Instrs[0]) {
 			n := 1
diff --git a/cl/compile_test.go b/cl/compile_test.go
index f1841da6..2d601ae2 100644
--- a/cl/compile_test.go
+++ b/cl/compile_test.go
@@ -28,12 +28,6 @@ func testCompile(t *testing.T, src, expected string) {
 	cltest.TestCompileEx(t, src, "foo.go", expected)
 }
 
-/*
-func TestFromTestgo(t *testing.T) {
-	cltest.FromDir(t, "strucintf", "./_testgo", false)
-}
-*/
-
 func TestFromTestpy(t *testing.T) {
 	cltest.FromDir(t, "", "./_testpy", false)
 }
diff --git a/cl/internal/foo/foo.go b/cl/internal/foo/foo.go
new file mode 100644
index 00000000..e385a31d
--- /dev/null
+++ b/cl/internal/foo/foo.go
@@ -0,0 +1,9 @@
+package foo
+
+func Bar() any {
+	return struct{ V int }{1}
+}
+
+func F() any {
+	return struct{ v int }{1}
+}
diff --git a/internal/abi/llgo_autogen.lla b/internal/abi/llgo_autogen.lla
index 505458a8..7fed6350 100644
Binary files a/internal/abi/llgo_autogen.lla and b/internal/abi/llgo_autogen.lla differ
diff --git a/internal/abi/type.go b/internal/abi/type.go
index 085a6475..21f90142 100644
--- a/internal/abi/type.go
+++ b/internal/abi/type.go
@@ -84,14 +84,12 @@ const (
 	UnsafePointer
 )
 
-/*
 const (
 	// TODO (khr, drchase) why aren't these in TFlag?  Investigate, fix if possible.
 	KindDirectIface = 1 << 5
 	KindGCProg      = 1 << 6 // Type.gc points to GC program
 	KindMask        = (1 << 5) - 1
 )
-*/
 
 // TFlag is used by a Type to signal what extra type information is
 // available in the memory directly following the Type value.
@@ -229,7 +227,7 @@ type Imethod struct {
 	Typ  TypeOff // .(*FuncType) underneath
 }
 
-func (t *Type) Kind() Kind { return Kind(t.Kind_) }
+func (t *Type) Kind() Kind { return Kind(t.Kind_ & KindMask) }
 
 // Size returns the size of data with type t.
 func (t *Type) Size() uintptr { return t.Size_ }
diff --git a/internal/runtime/llgo_autogen.lla b/internal/runtime/llgo_autogen.lla
index 3bb1386b..a5c5b75b 100644
Binary files a/internal/runtime/llgo_autogen.lla and b/internal/runtime/llgo_autogen.lla differ
diff --git a/internal/runtime/runtime2.go b/internal/runtime/runtime2.go
index d0d8bea7..027c408f 100644
--- a/internal/runtime/runtime2.go
+++ b/internal/runtime/runtime2.go
@@ -8,21 +8,20 @@ import (
 	"unsafe"
 )
 
-type iface struct {
-	tab  *itab
-	data unsafe.Pointer
-}
-
-/*
 type eface struct {
 	_type *_type
 	data  unsafe.Pointer
 }
 
+/*
 func efaceOf(ep *any) *eface {
 	return (*eface)(unsafe.Pointer(ep))
 }
-*/
+
+type iface struct {
+	tab  *itab
+	data unsafe.Pointer
+}
 
 // layout of Itab known to compilers
 // allocated in non-garbage-collected memory
@@ -35,3 +34,11 @@ type itab struct {
 	_     [4]byte
 	fun   [1]uintptr // variable sized. fun[0]==0 means _type does not implement inter.
 }
+
+func MakeInterface(inter *InterfaceType, typ *Type, data unsafe.Pointer) Interface {
+	tab := &itab{inter: inter, _type: typ, hash: 0, fun: [1]uintptr{0}}
+	return Interface{
+		tab: tab, data: data,
+	}
+}
+*/
diff --git a/internal/runtime/z_c.go b/internal/runtime/z_c.go
index 1ea1efbd..2689b8cc 100644
--- a/internal/runtime/z_c.go
+++ b/internal/runtime/z_c.go
@@ -40,8 +40,8 @@ func Zeroinit(p c.Pointer, size uintptr) c.Pointer {
 }
 
 // TracePanic prints panic message.
-func TracePanic(v Interface) {
-	kind := abi.Kind(v.tab._type.Kind_)
+func TracePanic(v Eface) {
+	kind := abi.Kind(v._type.Kind_)
 	switch {
 	case kind == abi.String:
 		stringTracef(c.Stderr, c.Str("panic: %s\n"), *(*String)(v.data))
diff --git a/internal/runtime/z_eface.go b/internal/runtime/z_eface.go
new file mode 100644
index 00000000..a0f96d03
--- /dev/null
+++ b/internal/runtime/z_eface.go
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package runtime
+
+import (
+	"unsafe"
+
+	"github.com/goplus/llgo/internal/abi"
+)
+
+type Eface = eface
+
+// -----------------------------------------------------------------------------
+
+func MakeAnyIntptr(typ *Type, data uintptr) Eface {
+	return eface{
+		_type: typ, data: unsafe.Pointer(data),
+	}
+}
+
+func MakeAnyString(data string) Eface {
+	typ := basicTypes[abi.String]
+	return eface{
+		_type: typ, data: unsafe.Pointer(&data),
+	}
+}
+
+func I2Int(v Eface, t *Type) uintptr {
+	if v._type == t {
+		return uintptr(v.data)
+	}
+	panic("I2Int: type mismatch")
+}
+
+func CheckI2Int(v Eface, t *Type) (uintptr, bool) {
+	if v._type == t {
+		return uintptr(v.data), true
+	}
+	return 0, false
+}
+
+func I2String(v Eface) string {
+	if v._type.Kind() == abi.String {
+		return *(*string)(v.data)
+	}
+	panic("I2String: type mismatch")
+}
+
+func CheckI2String(v Eface) (string, bool) {
+	if v._type.Kind() == abi.String {
+		return *(*string)(v.data), true
+	}
+	return "", false
+}
+
+// -----------------------------------------------------------------------------
diff --git a/internal/runtime/z_iface.go b/internal/runtime/z_iface.go
deleted file mode 100644
index c64449ca..00000000
--- a/internal/runtime/z_iface.go
+++ /dev/null
@@ -1,94 +0,0 @@
-/*
- * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package runtime
-
-import (
-	"unsafe"
-
-	"github.com/goplus/llgo/internal/abi"
-)
-
-// -----------------------------------------------------------------------------
-
-type InterfaceType = abi.InterfaceType
-
-var (
-	TyAny = &InterfaceType{}
-)
-
-// -----------------------------------------------------------------------------
-
-type Interface = iface
-
-func MakeAnyIntptr(typ *Type, data uintptr) Interface {
-	tab := &itab{inter: TyAny, _type: typ, hash: 0, fun: [1]uintptr{0}}
-	return Interface{
-		tab: tab, data: unsafe.Pointer(data),
-	}
-}
-
-func MakeAnyString(data string) Interface {
-	typ := basicTypes[abi.String]
-	tab := &itab{inter: TyAny, _type: typ, hash: 0, fun: [1]uintptr{0}}
-	return Interface{
-		tab: tab, data: unsafe.Pointer(&data),
-	}
-}
-
-func MakeAny(typ *Type, data unsafe.Pointer) Interface {
-	tab := &itab{inter: TyAny, _type: typ, hash: 0, fun: [1]uintptr{0}}
-	return Interface{
-		tab: tab, data: data,
-	}
-}
-
-func MakeInterface(inter *InterfaceType, typ *Type, data unsafe.Pointer) Interface {
-	tab := &itab{inter: inter, _type: typ, hash: 0, fun: [1]uintptr{0}}
-	return Interface{
-		tab: tab, data: data,
-	}
-}
-
-func I2Int(v Interface, t *Type) uintptr {
-	if v.tab._type == t {
-		return uintptr(v.data)
-	}
-	panic("I2Int: type mismatch")
-}
-
-func CheckI2Int(v Interface, t *Type) (uintptr, bool) {
-	if v.tab._type == t {
-		return uintptr(v.data), true
-	}
-	return 0, false
-}
-
-func I2String(v Interface, t *Type) string {
-	if v.tab._type == t {
-		return *(*string)(v.data)
-	}
-	panic("I2String: type mismatch")
-}
-
-func CheckI2String(v Interface, t *Type) (string, bool) {
-	if v.tab._type == t {
-		return *(*string)(v.data), true
-	}
-	return "", false
-}
-
-// -----------------------------------------------------------------------------
diff --git a/internal/runtime/z_print.go b/internal/runtime/z_print.go
index 4d4ea802..7aeca7f3 100644
--- a/internal/runtime/z_print.go
+++ b/internal/runtime/z_print.go
@@ -66,6 +66,6 @@ func PrintSlice(s Slice) {
 	print("[", s.len, "/", s.cap, "]", s.data)
 }
 
-func PrintIface(i Interface) {
-	print("(", i.tab, ",", i.data, ")")
+func PrintEface(e Eface) {
+	print("(", e._type, ",", e.data, ")")
 }
diff --git a/internal/runtime/z_type.go b/internal/runtime/z_type.go
index f9915453..a4860621 100644
--- a/internal/runtime/z_type.go
+++ b/internal/runtime/z_type.go
@@ -97,15 +97,16 @@ func StructField(name string, typ *Type, off uintptr, tag string, exported, embe
 
 // Struct returns a struct type.
 func Struct(size uintptr, pkgPath string, fields ...abi.StructField) *Type {
-	npkg := abi.NewName(pkgPath, "", false, false)
+	// TODO(xsw): pkgPath
+	// npkg := abi.NewName(pkgPath, "", false, false)
 	ret := &abi.StructType{
 		Type: Type{
 			Size_: size,
 			Hash:  uint32(abi.Struct), // TODO(xsw): hash
 			Kind_: uint8(abi.Struct),
 		},
-		PkgPath: npkg,
-		Fields:  fields,
+		// PkgPath: npkg,
+		Fields: fields,
 	}
 	return &ret.Type
 }
diff --git a/ssa/_abi/abi.go b/ssa/_abi/abi.go
deleted file mode 100644
index 65578218..00000000
--- a/ssa/_abi/abi.go
+++ /dev/null
@@ -1,73 +0,0 @@
-/*
- * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package abi
-
-import (
-	"crypto/sha256"
-	"encoding/base64"
-	"fmt"
-	"go/types"
-	"hash"
-)
-
-// Builder is a helper for constructing ABI types.
-type Builder struct {
-	h   hash.Hash
-	buf []byte
-}
-
-// New creates a new ABI type Builder.
-func New() *Builder {
-	h := sha256.New()
-	buf := make([]byte, sha256.Size)
-	return &Builder{h, buf}
-}
-
-// TypeName returns the ABI type name for the specified type.
-func (b *Builder) TypeName(t types.Type) string {
-	switch t := t.(type) {
-	case *types.Basic:
-		return t.Name()
-	case *types.Pointer:
-		return "*" + b.TypeName(t.Elem())
-	case *types.Struct:
-		return b.StructName(t)
-	}
-	panic("todo")
-}
-
-// StructName returns the ABI type name for the specified struct type.
-func (b *Builder) StructName(t *types.Struct) string {
-	hash := b.structHash(t)
-	return "struct$" + base64.RawURLEncoding.EncodeToString(hash)
-}
-
-func (b *Builder) structHash(t *types.Struct) []byte {
-	h := b.h
-	h.Reset()
-	n := t.NumFields()
-	fmt.Fprintln(h, "struct", n)
-	for i := 0; i < n; i++ {
-		f := t.Field(i)
-		name := f.Name()
-		if f.Embedded() {
-			name = "-"
-		}
-		fmt.Fprintln(h, name, b.TypeName(f.Type()))
-	}
-	return h.Sum(b.buf[:0])
-}
diff --git a/ssa/abi/abi.go b/ssa/abi/abi.go
new file mode 100644
index 00000000..042755f8
--- /dev/null
+++ b/ssa/abi/abi.go
@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package abi
+
+import (
+	"crypto/sha256"
+	"encoding/base64"
+	"fmt"
+	"go/types"
+	"hash"
+
+	"github.com/goplus/llgo/internal/abi"
+)
+
+// -----------------------------------------------------------------------------
+
+func BasicKind(t *types.Basic) abi.Kind {
+	kind := t.Kind()
+	switch kind {
+	case types.String:
+		return abi.String
+	case types.UnsafePointer:
+		return abi.UnsafePointer
+	}
+	return abi.Kind(kind)
+}
+
+// -----------------------------------------------------------------------------
+
+type Kind int
+
+const (
+	Invalid  Kind = iota
+	Indirect      // allocate memory for the value
+	Pointer       // store a pointer value directly in the interface value
+	Integer       // store a integer value directly in the interface value
+	BitCast       // store other value (need bitcast) directly in the interface value
+)
+
+func KindOf(raw types.Type, lvl int, is32Bits bool) (Kind, types.Type, int) {
+	switch t := raw.Underlying().(type) {
+	case *types.Basic:
+		kind := t.Kind()
+		switch {
+		case types.Bool <= kind && kind <= types.Uintptr:
+			if is32Bits && (kind == types.Int64 || kind == types.Uint64) {
+				return Indirect, raw, lvl
+			}
+			return Integer, raw, lvl
+		case kind == types.Float32:
+			return BitCast, raw, lvl
+		case kind == types.Float64 || kind == types.Complex64:
+			if is32Bits {
+				return Indirect, raw, lvl
+			}
+			return BitCast, raw, lvl
+		case kind == types.UnsafePointer:
+			return Pointer, raw, lvl
+		}
+	case *types.Pointer, *types.Signature, *types.Map, *types.Chan:
+		return Pointer, raw, lvl
+	case *types.Struct:
+		if t.NumFields() == 1 {
+			return KindOf(t.Field(0).Type(), lvl+1, is32Bits)
+		}
+	case *types.Interface, *types.Slice:
+	case *types.Array:
+		if t.Len() == 1 {
+			return KindOf(t.Elem(), lvl+1, is32Bits)
+		}
+	default:
+		panic("unkown type")
+	}
+	return Indirect, raw, lvl
+}
+
+// -----------------------------------------------------------------------------
+
+// Builder is a helper for constructing ABI types.
+type Builder struct {
+	h   hash.Hash
+	buf []byte
+	Pkg string
+}
+
+// New creates a new ABI type Builder.
+func New(pkg string) *Builder {
+	ret := new(Builder)
+	ret.Init(pkg)
+	return ret
+}
+
+func (b *Builder) Init(pkg string) {
+	b.Pkg = pkg
+	b.h = sha256.New()
+	b.buf = make([]byte, sha256.Size)
+}
+
+// TypeName returns the ABI type name for the specified type.
+func (b *Builder) TypeName(t types.Type) (ret string, private bool) {
+	switch t := t.(type) {
+	case *types.Basic:
+		return BasicName(t), false
+	case *types.Pointer:
+		ret, private = b.TypeName(t.Elem())
+		return "*" + ret, private
+	case *types.Struct:
+		return b.StructName(t)
+	}
+	panic("todo")
+}
+
+func BasicName(t *types.Basic) string {
+	return "_llgo_" + t.Name()
+}
+
+// StructName returns the ABI type name for the specified struct type.
+func (b *Builder) StructName(t *types.Struct) (ret string, private bool) {
+	hash, private := b.structHash(t)
+	hashStr := base64.RawURLEncoding.EncodeToString(hash)
+	if private {
+		return b.Pkg + ".struct$" + hashStr, true
+	}
+	return "_llgo_struct$" + hashStr, false
+}
+
+func (b *Builder) structHash(t *types.Struct) (ret []byte, private bool) {
+	h := b.h
+	h.Reset()
+	n := t.NumFields()
+	fmt.Fprintln(h, "struct", n)
+	for i := 0; i < n; i++ {
+		f := t.Field(i)
+		if !f.Exported() {
+			private = true
+		}
+		name := f.Name()
+		if f.Embedded() {
+			name = "-"
+		}
+		ft, fpriv := b.TypeName(f.Type())
+		if fpriv {
+			private = true
+		}
+		fmt.Fprintln(h, name, ft)
+	}
+	ret = h.Sum(b.buf[:0])
+	return
+}
+
+// -----------------------------------------------------------------------------
diff --git a/ssa/cl_test.go b/ssa/cl_test.go
index c89a0958..513944c1 100644
--- a/ssa/cl_test.go
+++ b/ssa/cl_test.go
@@ -25,6 +25,10 @@ import (
 	"github.com/goplus/llgo/ssa/ssatest"
 )
 
+func TestFromTestgo(t *testing.T) {
+	cltest.FromDir(t, "", "../cl/_testgo", false)
+}
+
 func TestFromTestpy(t *testing.T) {
 	cltest.FromDir(t, "", "../cl/_testpy", false)
 }
@@ -56,26 +60,34 @@ func TestMakeInterface(t *testing.T) {
 	ssatest.Assert(t, pkg, `; ModuleID = 'foo'
 source_filename = "foo"
 
-%"github.com/goplus/llgo/internal/runtime.iface" = type { ptr, ptr }
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
 
 define void @main() {
 _llgo_0:
-  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 8)
-  store i64 100, ptr %0, align 4
-  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 6)
-  %2 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAny"(ptr %1, ptr %0)
-  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 8)
-  store double 1.000000e+02, ptr %3, align 8
-  %4 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 14)
-  %5 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAny"(ptr %4, ptr %3)
+  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 6)
+  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 8)
+  store i64 100, ptr %1, align 4
+  %2 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %2, i32 0, i32 0
+  store ptr %0, ptr %3, align 8
+  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %2, i32 0, i32 1
+  store ptr %1, ptr %4, align 8
+  %5 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %2, align 8
+  %6 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 14)
+  %7 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 8)
+  store double 1.000000e+02, ptr %7, align 8
+  %8 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %8, i32 0, i32 0
+  store ptr %6, ptr %9, align 8
+  %10 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %8, i32 0, i32 1
+  store ptr %7, ptr %10, align 8
+  %11 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %8, align 8
   ret void
 }
 
-declare ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64)
-
-declare %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAny"(ptr, ptr)
-
 declare ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64)
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64)
 `)
 }
 
diff --git a/ssa/datastruct.go b/ssa/datastruct.go
index 0ce70e97..0ff80d6a 100644
--- a/ssa/datastruct.go
+++ b/ssa/datastruct.go
@@ -70,9 +70,8 @@ func (b Builder) StringData(x Expr) Expr {
 	if debugInstr {
 		log.Printf("StringData %v\n", x.impl)
 	}
-	prog := b.Prog
 	ptr := llvm.CreateExtractValue(b.impl, x.impl, 0)
-	return Expr{ptr, prog.CStr()}
+	return Expr{ptr, b.Prog.CStr()}
 }
 
 // StringLen returns the length of a string.
@@ -80,9 +79,8 @@ func (b Builder) StringLen(x Expr) Expr {
 	if debugInstr {
 		log.Printf("StringLen %v\n", x.impl)
 	}
-	prog := b.Prog
 	ptr := llvm.CreateExtractValue(b.impl, x.impl, 1)
-	return Expr{ptr, prog.Int()}
+	return Expr{ptr, b.Prog.Int()}
 }
 
 // SliceData returns the data pointer of a slice.
@@ -90,9 +88,8 @@ func (b Builder) SliceData(x Expr) Expr {
 	if debugInstr {
 		log.Printf("SliceData %v\n", x.impl)
 	}
-	prog := b.Prog
 	ptr := llvm.CreateExtractValue(b.impl, x.impl, 0)
-	return Expr{ptr, prog.CStr()}
+	return Expr{ptr, b.Prog.VoidPtr()}
 }
 
 // SliceLen returns the length of a slice.
@@ -100,9 +97,8 @@ func (b Builder) SliceLen(x Expr) Expr {
 	if debugInstr {
 		log.Printf("SliceLen %v\n", x.impl)
 	}
-	prog := b.Prog
 	ptr := llvm.CreateExtractValue(b.impl, x.impl, 1)
-	return Expr{ptr, prog.Int()}
+	return Expr{ptr, b.Prog.Int()}
 }
 
 // SliceCap returns the length of a slice cap.
@@ -110,9 +106,8 @@ func (b Builder) SliceCap(x Expr) Expr {
 	if debugInstr {
 		log.Printf("SliceCap %v\n", x.impl)
 	}
-	prog := b.Prog
 	ptr := llvm.CreateExtractValue(b.impl, x.impl, 2)
-	return Expr{ptr, prog.Int()}
+	return Expr{ptr, b.Prog.Int()}
 }
 
 // The IndexAddr instruction yields the address of the element at
@@ -188,7 +183,7 @@ func (b Builder) Index(x, idx Expr, addr func(Expr) Expr) Expr {
 		if addr != nil {
 			ptr = addr(x)
 		} else {
-			size := b.SizeOf(telem, t.Len())
+			size := SizeOf(prog, telem, t.Len())
 			ptr = b.Alloca(size)
 			b.Store(ptr, x)
 		}
@@ -240,7 +235,8 @@ func (b Builder) Slice(x, low, high, max Expr) (ret Expr) {
 	var nCap Expr
 	var nEltSize Expr
 	var base Expr
-	if low.IsNil() {
+	var lowIsNil = low.IsNil()
+	if lowIsNil {
 		low = prog.IntVal(0, prog.Int())
 	}
 	switch t := x.raw.Type.Underlying().(type) {
@@ -255,7 +251,7 @@ func (b Builder) Slice(x, low, high, max Expr) (ret Expr) {
 		ret.impl = b.InlineCall(b.Pkg.rtFunc("NewStringSlice"), x, low, high).impl
 		return
 	case *types.Slice:
-		nEltSize = b.SizeOf(prog.Index(x.Type))
+		nEltSize = SizeOf(prog, prog.Index(x.Type))
 		nCap = b.SliceCap(x)
 		if high.IsNil() {
 			high = b.SliceCap(x)
@@ -268,9 +264,12 @@ func (b Builder) Slice(x, low, high, max Expr) (ret Expr) {
 		case *types.Array:
 			elem := prog.rawType(te.Elem())
 			ret.Type = prog.Slice(elem)
-			nEltSize = b.SizeOf(elem)
+			nEltSize = SizeOf(prog, elem)
 			nCap = prog.IntVal(uint64(te.Len()), prog.Int())
 			if high.IsNil() {
+				if lowIsNil && max.IsNil() {
+					return b.unsafeSlice(x, nCap.impl, nCap.impl)
+				}
 				high = nCap
 			}
 			base = x
@@ -283,6 +282,18 @@ func (b Builder) Slice(x, low, high, max Expr) (ret Expr) {
 	return
 }
 
+// SliceLit creates a new slice with the specified elements.
+func (b Builder) SliceLit(t Type, elts ...Expr) Expr {
+	prog := b.Prog
+	telem := prog.Index(t)
+	ptr := b.AllocU(telem, int64(len(elts)))
+	for i, elt := range elts {
+		b.Store(b.Advance(ptr, prog.Val(i)), elt)
+	}
+	size := llvm.ConstInt(prog.tyInt(), uint64(len(elts)), false)
+	return b.unsafeSlice(ptr, size, size)
+}
+
 // -----------------------------------------------------------------------------
 
 // The MakeMap instruction creates a new hash-table-based map object
@@ -323,10 +334,11 @@ func (b Builder) MakeSlice(t Type, len, cap Expr) (ret Expr) {
 		log.Printf("MakeSlice %v, %v, %v\n", t.RawType(), len.impl, cap.impl)
 	}
 	pkg := b.Pkg
+	prog := b.Prog
 	if cap.IsNil() {
 		cap = len
 	}
-	elemSize := b.SizeOf(b.Prog.Index(t))
+	elemSize := SizeOf(prog, prog.Index(t))
 	size := b.BinOp(token.MUL, cap, elemSize)
 	ptr := b.InlineCall(pkg.rtFunc("AllocZ"), size)
 	ret.impl = b.InlineCall(pkg.rtFunc("NewSlice"), ptr, len, cap).impl
diff --git a/ssa/decl.go b/ssa/decl.go
index 97856aa3..2ff49cde 100644
--- a/ssa/decl.go
+++ b/ssa/decl.go
@@ -58,6 +58,13 @@ type aNamedConst struct {
 // it augments with the name and position of its 'const' declaration.
 type NamedConst = *aNamedConst
 
+/*
+// NewConst creates a new named constant.
+func (p Package) NewConst(name string, val constant.Value) NamedConst {
+	return &aNamedConst{}
+}
+*/
+
 // -----------------------------------------------------------------------------
 
 type aGlobal struct {
@@ -75,9 +82,21 @@ func (p Package) NewVar(name string, typ types.Type, bg Background) Global {
 		return v
 	}
 	t := p.Prog.Type(typ, bg)
+	return p.doNewVar(name, t)
+}
+
+// NewVarFrom creates a new global variable.
+func (p Package) NewVarFrom(name string, t Type) Global {
+	if v, ok := p.vars[name]; ok {
+		return v
+	}
+	return p.doNewVar(name, t)
+}
+
+func (p Package) doNewVar(name string, t Type) Global {
 	var gbl llvm.Value
 	var array bool
-	if t.kind == vkPtr && p.Prog.Elem(t).kind == vkArray {
+	if t.kind == vkPtr && p.Prog.Elem(t).kind == vkArray { // TODO(xsw): check this code
 		typ := p.Prog.Elem(t).ll
 		gbl = llvm.AddGlobal(p.mod, typ, name)
 		gbl.SetInitializer(llvm.Undef(typ))
@@ -97,7 +116,7 @@ func (p Package) VarOf(name string) Global {
 
 // Init initializes the global variable with the given value.
 func (g Global) Init(v Expr) {
-	if g.array && v.kind == vkPtr {
+	if g.array && v.kind == vkPtr { // TODO(xsw): check this code
 		return
 	}
 	g.impl.SetInitializer(v.impl)
@@ -219,6 +238,13 @@ func newParams(fn Type, prog Program) (params []Type, hasVArg bool) {
 	return
 }
 
+/*
+// Name returns the function's name.
+func (p Function) Name() string {
+	return p.impl.Name()
+}
+*/
+
 // Params returns the function's ith parameter.
 func (p Function) Param(i int) Expr {
 	i += p.base // skip if hasFreeVars
@@ -248,7 +274,7 @@ func (p Function) NewBuilder() Builder {
 	b := prog.ctx.NewBuilder()
 	// TODO(xsw): Finalize may cause panic, so comment it.
 	// b.Finalize()
-	return &aBuilder{b, p, p.Pkg, prog}
+	return &aBuilder{b, nil, p, p.Pkg, prog}
 }
 
 // HasBody reports whether the function has a body.
@@ -261,7 +287,8 @@ func (p Function) HasBody() bool {
 func (p Function) MakeBody(nblk int) Builder {
 	p.MakeBlocks(nblk)
 	b := p.NewBuilder()
-	b.impl.SetInsertPointAtEnd(p.blks[0].impl)
+	b.blk = p.blks[0]
+	b.impl.SetInsertPointAtEnd(b.blk.last)
 	return b
 }
 
@@ -280,7 +307,7 @@ func (p Function) MakeBlocks(nblk int) []BasicBlock {
 func (p Function) addBlock(idx int) BasicBlock {
 	label := "_llgo_" + strconv.Itoa(idx)
 	blk := llvm.AddBasicBlock(p.impl, label)
-	ret := &aBasicBlock{blk, p, idx}
+	ret := &aBasicBlock{blk, blk, p, idx}
 	p.blks = append(p.blks, ret)
 	return ret
 }
@@ -350,15 +377,14 @@ func (p Package) PyObjOf(name string) PyObjRef {
 	return p.pyobjs[name]
 }
 
-// PyLoadModSyms loads module symbols used in this package.
-func (p Package) PyLoadModSyms(b Builder, ret BasicBlock) {
-	objs := p.pyobjs
-	n := len(objs)
-	if n == 0 {
-		return
-	}
+func (p Package) pyHasModSyms() bool {
+	return len(p.pyobjs) > 0
+}
 
-	names := make([]string, 0, n)
+// pyLoadModSyms loads module symbols used in this package.
+func (p Package) pyLoadModSyms(b Builder) {
+	objs := p.pyobjs
+	names := make([]string, 0, len(objs))
 	for name := range objs {
 		names = append(names, name)
 	}
@@ -376,7 +402,6 @@ func (p Package) PyLoadModSyms(b Builder, ret BasicBlock) {
 		}
 	}
 
-	b.SetBlockEx(ret, afterInit)
 	for _, modName := range modNames {
 		objs := mods[modName]
 		b.PyLoadModSyms(modName, objs...)
diff --git a/ssa/expr.go b/ssa/expr.go
index 49ccc6d9..6fce4fbe 100644
--- a/ssa/expr.go
+++ b/ssa/expr.go
@@ -93,6 +93,40 @@ func phisExpr(t Type, phis []llvm.Value) Expr {
 
 // -----------------------------------------------------------------------------
 
+func (p Program) Zero(t Type) Expr {
+	var ret llvm.Value
+	switch u := t.raw.Type.Underlying().(type) {
+	case *types.Basic:
+		kind := u.Kind()
+		switch {
+		case kind >= types.Bool && kind <= types.Uintptr:
+			ret = llvm.ConstInt(p.rawType(u).ll, 0, false)
+		case kind == types.String:
+			ret = p.Zero(p.rtType("String")).impl
+		case kind == types.UnsafePointer:
+			ret = llvm.ConstPointerNull(p.tyVoidPtr())
+		case kind <= types.Float64:
+			ret = llvm.ConstFloat(p.Float64().ll, 0)
+		case kind == types.Float32:
+			ret = llvm.ConstFloat(p.Float32().ll, 0)
+		default:
+			panic("todo")
+		}
+	case *types.Pointer:
+		return Expr{llvm.ConstNull(t.ll), t}
+	case *types.Struct:
+		n := u.NumFields()
+		flds := make([]llvm.Value, n)
+		for i := 0; i < n; i++ {
+			flds[i] = p.Zero(p.rawType(u.Field(i).Type())).impl
+		}
+		ret = llvm.ConstStruct(flds, false)
+	default:
+		log.Panicln("todo:", u)
+	}
+	return Expr{ret, t}
+}
+
 // Null returns a null constant expression.
 func (p Program) Null(t Type) Expr {
 	return Expr{llvm.ConstNull(t.ll), t}
@@ -125,12 +159,6 @@ func (p Program) FloatVal(v float64, t Type) Expr {
 	return Expr{ret, t}
 }
 
-func (p Program) ByteVal(v byte) Expr {
-	t := p.Byte()
-	ret := llvm.ConstInt(t.ll, uint64(v), false)
-	return Expr{ret, t}
-}
-
 // Val returns a constant expression.
 func (p Program) Val(v interface{}) Expr {
 	switch v := v.(type) {
@@ -180,13 +208,6 @@ func (b Builder) Const(v constant.Value, typ Type) Expr {
 	panic(fmt.Sprintf("unsupported Const: %v, %v", v, raw))
 }
 
-// SizeOf returns the size of a type.
-func (b Builder) SizeOf(t Type, n ...int64) Expr {
-	prog := b.Prog
-	size := prog.SizeOf(t, n...)
-	return prog.IntVal(size, prog.Uintptr())
-}
-
 // CStr returns a c-style string constant expression.
 func (b Builder) CStr(v string) Expr {
 	return Expr{llvm.CreateGlobalStringPtr(b.impl, v), b.Prog.CStr()}
@@ -200,10 +221,17 @@ func (b Builder) Str(v string) (ret Expr) {
 	return Expr{aggregateValue(b.impl, prog.rtString(), data, size), prog.String()}
 }
 
-// unsafe.String(data *byte, size int) string
-func (b Builder) String(data, size Expr) Expr {
+// unsafeString(data *byte, size int) string
+func (b Builder) unsafeString(data, size llvm.Value) Expr {
 	prog := b.Prog
-	return Expr{aggregateValue(b.impl, prog.rtString(), data.impl, size.impl), prog.String()}
+	return Expr{aggregateValue(b.impl, prog.rtString(), data, size), prog.String()}
+}
+
+// unsafeSlice(data *T, size, cap int) []T
+func (b Builder) unsafeSlice(data Expr, size, cap llvm.Value) Expr {
+	prog := b.Prog
+	tslice := prog.Slice(prog.Elem(data.Type))
+	return Expr{aggregateValue(b.impl, prog.rtSlice(), data.impl, size, cap), tslice}
 }
 
 // -----------------------------------------------------------------------------
@@ -397,7 +425,7 @@ func (b Builder) UnOp(op token.Token, x Expr) (ret Expr) {
 	case token.MUL:
 		return b.Load(x)
 	case token.SUB:
-		switch t := x.Type.raw.Underlying().(type) {
+		switch t := x.raw.Type.Underlying().(type) {
 		case *types.Basic:
 			ret.Type = x.Type
 			if t.Info()&types.IsInteger != 0 {
@@ -489,10 +517,10 @@ func llvmDelayValues(f func(i int) Expr, n int) []llvm.Value {
 	return ret
 }
 
-func llvmBlocks(bblks []BasicBlock) []llvm.BasicBlock {
-	ret := make([]llvm.BasicBlock, len(bblks))
-	for i, v := range bblks {
-		ret[i] = v.impl
+func llvmPredBlocks(preds []BasicBlock) []llvm.BasicBlock {
+	ret := make([]llvm.BasicBlock, len(preds))
+	for i, v := range preds {
+		ret[i] = v.last
 	}
 	return ret
 }
@@ -503,24 +531,24 @@ type Phi struct {
 }
 
 // AddIncoming adds incoming values to a phi node.
-func (p Phi) AddIncoming(b Builder, bblks []BasicBlock, f func(i int) Expr) {
-	bs := llvmBlocks(bblks)
+func (p Phi) AddIncoming(b Builder, preds []BasicBlock, f func(i int) Expr) {
+	bs := llvmPredBlocks(preds)
 	if p.kind != vkPhisExpr { // normal phi node
-		vs := llvmDelayValues(f, len(bblks))
+		vs := llvmDelayValues(f, len(preds))
 		p.impl.AddIncoming(vs, bs)
 		return
 	}
 	e := p.raw.Type.(*phisExprTy)
 	phis := e.phis
 	vals := make([][]llvm.Value, len(phis))
-	for iblk, blk := range bblks {
-		last := blk.impl.LastInstruction()
+	for iblk, blk := range preds {
+		last := blk.last.LastInstruction()
 		b.impl.SetInsertPointBefore(last)
 		impl := b.impl
 		val := f(iblk).impl
 		for i := range phis {
 			if iblk == 0 {
-				vals[i] = make([]llvm.Value, len(bblks))
+				vals[i] = make([]llvm.Value, len(preds))
 			}
 			vals[i][iblk] = llvm.CreateExtractValue(impl, val, i)
 		}
@@ -667,7 +695,7 @@ func (b Builder) Alloc(elem Type, heap bool) (ret Expr) {
 	}
 	prog := b.Prog
 	pkg := b.Pkg
-	size := b.SizeOf(elem)
+	size := SizeOf(prog, elem)
 	if heap {
 		ret = b.InlineCall(pkg.rtFunc("AllocZ"), size)
 	} else {
@@ -683,9 +711,10 @@ func (b Builder) AllocU(elem Type, n ...int64) (ret Expr) {
 	if debugInstr {
 		log.Printf("AllocU %v, %v\n", elem.raw.Type, n)
 	}
-	size := b.SizeOf(elem, n...)
+	prog := b.Prog
+	size := SizeOf(prog, elem, n...)
 	ret = b.InlineCall(b.Pkg.rtFunc("AllocU"), size)
-	ret.Type = b.Prog.Pointer(elem)
+	ret.Type = prog.Pointer(elem)
 	return
 }
 
@@ -940,21 +969,6 @@ func (b Builder) Call(fn Expr, args ...Expr) (ret Expr) {
 	return
 }
 
-// The Extract instruction yields component Index of Tuple.
-//
-// This is used to access the results of instructions with multiple
-// return values, such as Call, TypeAssert, Next, UnOp(ARROW) and
-// IndexExpr(Map).
-//
-// Example printed form:
-//
-//	t1 = extract t0 #1
-func (b Builder) Extract(x Expr, index int) (ret Expr) {
-	ret.Type = b.Prog.toType(x.Type.raw.Type.(*types.Tuple).At(index).Type())
-	ret.impl = llvm.CreateExtractValue(b.impl, x.impl, index)
-	return
-}
-
 // A Builtin represents a specific use of a built-in function, e.g. len.
 //
 // Builtins are immutable values.  Builtins do not have addresses.
@@ -1008,7 +1022,7 @@ func (b Builder) BuiltinCall(fn string, args ...Expr) (ret Expr) {
 		ret.Type = prog.Void()
 		for i, arg := range args {
 			if ln && i > 0 {
-				b.InlineCall(b.Pkg.rtFunc("PrintByte"), prog.ByteVal(' '))
+				b.InlineCall(b.Pkg.rtFunc("PrintByte"), prog.IntVal(' ', prog.Byte()))
 			}
 			var fn string
 			typ := arg.Type
@@ -1035,8 +1049,8 @@ func (b Builder) BuiltinCall(fn string, args ...Expr) (ret Expr) {
 				typ = prog.VoidPtr()
 			case vkString:
 				fn = "PrintString"
-			case vkInterface:
-				fn = "PrintIface"
+			case vkEface:
+				fn = "PrintEface"
 			// case vkComplex:
 			// 	fn = "PrintComplex"
 			default:
@@ -1048,7 +1062,7 @@ func (b Builder) BuiltinCall(fn string, args ...Expr) (ret Expr) {
 			b.InlineCall(b.Pkg.rtFunc(fn), arg)
 		}
 		if ln {
-			b.InlineCall(b.Pkg.rtFunc("PrintByte"), prog.ByteVal('\n'))
+			b.InlineCall(b.Pkg.rtFunc("PrintByte"), prog.IntVal('\n', prog.Byte()))
 		}
 		return
 	case "copy":
@@ -1067,7 +1081,10 @@ func (b Builder) BuiltinCall(fn string, args ...Expr) (ret Expr) {
 			}
 		}
 	case "String": // unsafe.String
-		return b.String(args[0], args[1])
+		return b.unsafeString(args[0].impl, args[1].impl)
+	case "Slice": // unsafe.Slice
+		size := args[1].impl
+		return b.unsafeSlice(args[0], size, size)
 	}
 	panic("todo: " + fn)
 }
diff --git a/ssa/interface.go b/ssa/interface.go
index 16004054..c1104663 100644
--- a/ssa/interface.go
+++ b/ssa/interface.go
@@ -20,36 +20,107 @@ import (
 	"go/token"
 	"go/types"
 	"log"
+	"unsafe"
 
-	"github.com/goplus/llgo/internal/abi"
+	"github.com/goplus/llgo/ssa/abi"
 	"github.com/goplus/llvm"
 )
 
 // -----------------------------------------------------------------------------
 
 // abiBasic returns the abi type of the specified basic kind.
-func (b Builder) abiBasic(kind types.BasicKind) Expr {
-	return b.InlineCall(b.Pkg.rtFunc("Basic"), b.Prog.Val(int(kind)))
+func (b Builder) abiBasic(t *types.Basic) Expr {
+	/*
+		TODO(xsw):
+		name := abi.BasicName(t)
+		g := b.Pkg.NewVarFrom(name, b.Prog.AbiTypePtrPtr())
+		return b.Load(g.Expr)
+	*/
+	kind := int(abi.BasicKind(t))
+	return b.InlineCall(b.Pkg.rtFunc("Basic"), b.Prog.Val(kind))
 }
 
-/*
 // abiStruct returns the abi type of the specified struct type.
 func (b Builder) abiStruct(t *types.Struct) Expr {
-	// name := "__llgo_" + b.Prog.abi.StructName(t)
+	pkg := b.Pkg
+	name, private := pkg.abi.StructName(t)
+	g := pkg.VarOf(name)
+	if g == nil {
+		prog := b.Prog
+		g = pkg.doNewVar(name, prog.AbiTypePtrPtr())
+		g.Init(prog.Null(g.Type))
+		pub := !private
+		if pub {
+			g.impl.SetLinkage(llvm.LinkOnceAnyLinkage)
+		}
+		pkg.abiini = append(pkg.abiini, func(param unsafe.Pointer) {
+			b := Builder(param)
+			expr := g.Expr
+			var blks []BasicBlock
+			if pub {
+				eq := b.BinOp(token.EQL, b.Load(expr), b.Prog.Null(expr.Type))
+				blks = b.Func.MakeBlocks(2)
+				b.If(eq, blks[0], blks[1])
+				b.SetBlockEx(blks[0], AtEnd, false)
+			}
+			tabi := b.structOf(t)
+			b.Store(expr, tabi)
+			if pub {
+				b.Jump(blks[1])
+				b.SetBlockEx(blks[1], AtEnd, false)
+				b.blk.last = blks[1].last
+			}
+		})
+	}
+	return b.Load(g.Expr)
 }
-*/
 
-// AbiType returns the abi type of the specified type.
-func (b Builder) AbiType(t Type) Expr {
-	switch tx := t.raw.Type.(type) {
+// func Struct(size uintptr, pkgPath string, fields []abi.StructField) *abi.Type
+func (b Builder) structOf(t *types.Struct) Expr {
+	pkg := b.Pkg
+	prog := b.Prog
+	n := t.NumFields()
+	flds := make([]Expr, n)
+	strucAbi := pkg.rtFunc("Struct")
+	sfAbi := pkg.rtFunc("StructField")
+	typ := prog.rawType(t)
+	for i := 0; i < n; i++ {
+		f := t.Field(i)
+		off := uintptr(prog.OffsetOf(typ, i))
+		flds[i] = b.structField(sfAbi, prog, f, off, t.Tag(i))
+	}
+	pkgPath := b.Str(pkg.abi.Pkg)
+	params := strucAbi.raw.Type.(*types.Signature).Params()
+	tSlice := prog.rawType(params.At(params.Len() - 1).Type().(*types.Slice))
+	fldSlice := b.SliceLit(tSlice, flds...)
+	return b.Call(strucAbi, pkgPath, fldSlice)
+}
+
+// func StructField(name string, typ *abi.Type, off uintptr, tag string, exported, embedded bool) abi.StructField
+func (b Builder) structField(sfAbi Expr, prog Program, f *types.Var, offset uintptr, tag string) Expr {
+	name := b.Str(f.Name())
+	typ := b.abiType(f.Type())
+	exported := prog.Val(f.Exported())
+	embedded := prog.Val(f.Embedded())
+	return b.Call(sfAbi, name, typ, prog.Val(offset), b.Str(tag), exported, embedded)
+}
+
+// abiType returns the abi type of the specified type.
+func (b Builder) abiType(raw types.Type) Expr {
+	switch tx := raw.(type) {
 	case *types.Basic:
-		return b.abiBasic(tx.Kind())
-		//case *types.Struct:
-		//	return b.abiStruct(tx)
+		return b.abiBasic(tx)
+	case *types.Struct:
+		return b.abiStruct(tx)
 	}
 	panic("todo")
 }
 
+// unsafeEface(t *abi.Type, data unsafe.Pointer) Eface
+func (b Builder) unsafeEface(t, data llvm.Value) llvm.Value {
+	return aggregateValue(b.impl, b.Prog.rtEface(), t, data)
+}
+
 // -----------------------------------------------------------------------------
 
 // MakeInterface constructs an instance of an interface type from a
@@ -73,60 +144,84 @@ func (b Builder) MakeInterface(tinter Type, x Expr) (ret Expr) {
 	}
 	prog := b.Prog
 	typ := x.Type
-	switch tx := typ.raw.Type.Underlying().(type) {
-	case *types.Basic:
-		kind := tx.Kind()
-		switch {
-		case kind >= types.Bool && kind <= types.Uintptr:
-			if prog.is32Bits && (kind == types.Int64 || kind == types.Uint64) {
-				return b.makeIntfAlloc(tinter, rawIntf, typ, x)
-			}
-			return b.makeIntfByIntptr(tinter, rawIntf, typ, x.impl)
-		case kind == types.Float32:
-			i32 := llvm.CreateBitCast(b.impl, x.impl, prog.tyInt32())
-			return b.makeIntfByIntptr(tinter, rawIntf, typ, i32)
-		case kind == types.Float64:
-			if prog.is32Bits {
-				return b.makeIntfAlloc(tinter, rawIntf, typ, x)
-			}
-			i64 := llvm.CreateBitCast(b.impl, x.impl, prog.tyInt64())
-			return b.makeIntfByIntptr(tinter, rawIntf, typ, i64)
-		case kind == types.String:
-			return Expr{b.InlineCall(b.Pkg.rtFunc("MakeAnyString"), x).impl, tinter}
+	tabi := b.abiType(typ.raw.Type)
+	kind, _, lvl := abi.KindOf(typ.raw.Type, 0, prog.is32Bits)
+	switch kind {
+	case abi.Indirect:
+		vptr := b.AllocU(typ)
+		b.Store(vptr, x)
+		return Expr{b.unsafeEface(tabi.impl, vptr.impl), tinter}
+	}
+	ximpl := x.impl
+	if lvl > 0 {
+		ximpl = extractVal(b.impl, ximpl, lvl)
+	}
+	var u llvm.Value
+	switch kind {
+	case abi.Pointer:
+		return Expr{b.unsafeEface(tabi.impl, ximpl), tinter}
+	case abi.Integer:
+		tu := prog.Uintptr()
+		u = llvm.CreateIntCast(b.impl, ximpl, tu.ll)
+	case abi.BitCast:
+		tu := prog.Uintptr()
+		u = llvm.CreateBitCast(b.impl, ximpl, tu.ll)
+	default:
+		panic("todo")
+	}
+	data := llvm.CreateIntToPtr(b.impl, u, prog.tyVoidPtr())
+	return Expr{b.unsafeEface(tabi.impl, data), tinter}
+}
+
+func (b Builder) valFromData(typ Type, data llvm.Value) Expr {
+	prog := b.Prog
+	kind, real, lvl := abi.KindOf(typ.raw.Type, 0, prog.is32Bits)
+	switch kind {
+	case abi.Indirect:
+		impl := b.impl
+		tll := typ.ll
+		tptr := llvm.PointerType(tll, 0)
+		ptr := llvm.CreatePointerCast(impl, data, tptr)
+		return Expr{llvm.CreateLoad(impl, tll, ptr), typ}
+	}
+	t := typ
+	if lvl > 0 {
+		t = prog.rawType(real)
+	}
+	switch kind {
+	case abi.Pointer:
+		return b.buildVal(typ, data, lvl)
+	case abi.Integer:
+		x := castUintptr(b, data, prog.Uintptr())
+		return b.buildVal(typ, castInt(b, x, t), lvl)
+	case abi.BitCast:
+		x := castUintptr(b, data, prog.Uintptr())
+		if int(prog.SizeOf(t)) != prog.PointerSize() {
+			x = castInt(b, x, prog.Int32())
 		}
-		/* case *types.Struct:
-		size := int(prog.SizeOf(typ))
-		if size > prog.PointerSize() {
-			return b.makeIntfAlloc(tinter, rawIntf, typ, x)
-		}
-		tv := prog.ctx.IntType(size * 8)
-		iv := llvm.CreateBitCast(b.impl, x.impl, tv)
-		return b.makeIntfByIntptr(tinter, rawIntf, typ, iv) */
+		return b.buildVal(typ, llvm.CreateBitCast(b.impl, x, t.ll), lvl)
 	}
 	panic("todo")
 }
 
-func (b Builder) makeIntfAlloc(tinter Type, rawIntf *types.Interface, typ Type, x Expr) (ret Expr) {
-	vptr := b.AllocU(typ)
-	b.Store(vptr, x)
-	return b.makeIntfByPtr(tinter, rawIntf, typ, vptr)
-}
-
-func (b Builder) makeIntfByPtr(tinter Type, rawIntf *types.Interface, typ Type, vptr Expr) (ret Expr) {
-	if rawIntf.Empty() {
-		ret = b.InlineCall(b.Pkg.rtFunc("MakeAny"), b.AbiType(typ), vptr)
-		ret.Type = tinter
-		return
+func extractVal(b llvm.Builder, val llvm.Value, lvl int) llvm.Value {
+	for lvl > 0 {
+		// TODO(xsw): check array support
+		val = llvm.CreateExtractValue(b, val, 0)
+		lvl--
 	}
-	panic("todo")
+	return val
 }
 
-func (b Builder) makeIntfByIntptr(tinter Type, rawIntf *types.Interface, typ Type, x llvm.Value) (ret Expr) {
-	if rawIntf.Empty() {
-		tptr := b.Prog.Uintptr()
-		x = llvm.CreateIntCast(b.impl, x, tptr.ll)
-		impl := b.InlineCall(b.Pkg.rtFunc("MakeAnyIntptr"), b.AbiType(typ), Expr{x, tptr}).impl
-		return Expr{impl, tinter}
+func (b Builder) buildVal(typ Type, val llvm.Value, lvl int) Expr {
+	if lvl == 0 {
+		return Expr{val, typ}
+	}
+	switch t := typ.raw.Type.Underlying().(type) {
+	case *types.Struct:
+		telem := b.Prog.rawType(t.Field(0).Type())
+		elem := b.buildVal(telem, val, lvl-1)
+		return Expr{aggregateValue(b.impl, typ.ll, elem.impl), typ}
 	}
 	panic("todo")
 }
@@ -170,10 +265,40 @@ func (b Builder) makeIntfByIntptr(tinter Type, rawIntf *types.Interface, typ Typ
 //
 //	t1 = typeassert t0.(int)
 //	t3 = typeassert,ok t2.(T)
+func (b Builder) TypeAssert(x Expr, assertedTyp Type, commaOk bool) Expr {
+	if debugInstr {
+		log.Printf("TypeAssert %v, %v, %v\n", x.impl, assertedTyp.raw.Type, commaOk)
+	}
+	tx := b.faceAbiType(x)
+	tabi := b.abiType(assertedTyp.raw.Type)
+	eq := b.BinOp(token.EQL, tx, tabi)
+	if commaOk {
+		prog := b.Prog
+		t := prog.Tuple(assertedTyp, prog.Bool())
+		val := b.valFromData(assertedTyp, b.faceData(x.impl))
+		zero := prog.Zero(assertedTyp)
+		valTrue := aggregateValue(b.impl, t.ll, val.impl, prog.BoolVal(true).impl)
+		valFalse := aggregateValue(b.impl, t.ll, zero.impl, prog.BoolVal(false).impl)
+		return Expr{llvm.CreateSelect(b.impl, eq.impl, valTrue, valFalse), t}
+	}
+	blks := b.Func.MakeBlocks(2)
+	b.If(eq, blks[0], blks[1])
+	b.SetBlockEx(blks[1], AtEnd, false)
+	b.Panic(b.Str("type assertion failed"))
+	b.SetBlockEx(blks[0], AtEnd, false)
+	b.blk.last = blks[0].last
+	return b.valFromData(assertedTyp, b.faceData(x.impl))
+}
+
+/*
 func (b Builder) TypeAssert(x Expr, assertedTyp Type, commaOk bool) (ret Expr) {
 	if debugInstr {
 		log.Printf("TypeAssert %v, %v, %v\n", x.impl, assertedTyp.raw.Type, commaOk)
 	}
+	// TODO(xsw)
+	// if x.kind != vkEface {
+	//	 panic("todo: non empty interface")
+	// }
 	switch assertedTyp.kind {
 	case vkSigned, vkUnsigned, vkFloat, vkBool:
 		pkg := b.Pkg
@@ -183,13 +308,14 @@ func (b Builder) TypeAssert(x Expr, assertedTyp Type, commaOk bool) (ret Expr) {
 		}
 		fn := pkg.rtFunc(fnName)
 		var kind types.BasicKind
+		var typ Expr
 		switch t := assertedTyp.raw.Type.(type) {
 		case *types.Basic:
 			kind = t.Kind()
+			typ = b.abiBasic(t)
 		default:
 			panic("todo")
 		}
-		typ := b.InlineCall(pkg.rtFunc("Basic"), b.Prog.Val(int(kind)))
 		ret = b.InlineCall(fn, x, typ)
 		if kind != types.Uintptr {
 			conv := func(v llvm.Value) llvm.Value {
@@ -226,11 +352,32 @@ func (b Builder) TypeAssert(x Expr, assertedTyp Type, commaOk bool) (ret Expr) {
 		if commaOk {
 			fnName = "CheckI2String"
 		}
-		fn := pkg.rtFunc(fnName)
-		typ := b.InlineCall(pkg.rtFunc("Basic"), b.Prog.Val(int(abi.String)))
-		return b.InlineCall(fn, x, typ)
+		return b.InlineCall(pkg.rtFunc(fnName), x)
 	}
 	panic("todo")
 }
+*/
+
+// -----------------------------------------------------------------------------
+
+// InterfaceData returns the data pointer of an interface.
+func (b Builder) InterfaceData(x Expr) Expr {
+	if debugInstr {
+		log.Printf("InterfaceData %v\n", x.impl)
+	}
+	return Expr{b.faceData(x.impl), b.Prog.VoidPtr()}
+}
+
+func (b Builder) faceData(x llvm.Value) llvm.Value {
+	return llvm.CreateExtractValue(b.impl, x, 1)
+}
+
+func (b Builder) faceAbiType(x Expr) Expr {
+	if x.kind == vkIface {
+		panic("todo")
+	}
+	typ := llvm.CreateExtractValue(b.impl, x.impl, 0)
+	return Expr{typ, b.Prog.AbiTypePtr()}
+}
 
 // -----------------------------------------------------------------------------
diff --git a/ssa/package.go b/ssa/package.go
index 9e9356bb..da180b66 100644
--- a/ssa/package.go
+++ b/ssa/package.go
@@ -19,7 +19,9 @@ package ssa
 import (
 	"go/token"
 	"go/types"
+	"unsafe"
 
+	"github.com/goplus/llgo/ssa/abi"
 	"github.com/goplus/llvm"
 	"golang.org/x/tools/go/types/typeutil"
 )
@@ -99,7 +101,6 @@ type aProgram struct {
 	ctx   llvm.Context
 	typs  typeutil.Map // rawType -> Type
 	gocvt goTypes
-	//abi *abi.Builder
 
 	rt    *types.Package
 	rtget func() *types.Package
@@ -122,7 +123,7 @@ type aProgram struct {
 	voidPtrTy llvm.Type
 
 	rtStringTy llvm.Type
-	rtIfaceTy  llvm.Type
+	rtEfaceTy  llvm.Type
 	rtSliceTy  llvm.Type
 	rtMapTy    llvm.Type
 
@@ -137,6 +138,7 @@ type aProgram struct {
 	intTy     Type
 	uintTy    Type
 	f64Ty     Type
+	f32Ty     Type
 	byteTy    Type
 	i32Ty     Type
 	u32Ty     Type
@@ -144,6 +146,9 @@ type aProgram struct {
 	u64Ty     Type
 	pyObjPtr  Type
 	pyObjPPtr Type
+	abiTyptr  Type
+	abiTypptr Type
+	efaceTy   Type
 
 	pyImpTy    *types.Signature
 	pyNewList  *types.Signature
@@ -184,7 +189,7 @@ func NewProgram(target *Target) Program {
 	*/
 	is32Bits := (td.PointerSize() == 4 || target.GOARCH == "x86") // TODO(xsw): remove temp code
 	return &aProgram{
-		ctx: ctx, gocvt: newGoTypes(), // abi: abi.New(),
+		ctx: ctx, gocvt: newGoTypes(),
 		target: target, td: td, is32Bits: is32Bits,
 		named: make(map[string]llvm.Type),
 	}
@@ -243,11 +248,11 @@ func (p Program) rtType(name string) Type {
 	return p.rawType(p.rtNamed(name))
 }
 
-func (p Program) rtIface() llvm.Type {
-	if p.rtIfaceTy.IsNil() {
-		p.rtIfaceTy = p.rtType("Interface").ll
+func (p Program) rtEface() llvm.Type {
+	if p.rtEfaceTy.IsNil() {
+		p.rtEfaceTy = p.rtType("Eface").ll
 	}
-	return p.rtIfaceTy
+	return p.rtEfaceTy
 }
 
 func (p Program) rtMap() llvm.Type {
@@ -284,7 +289,44 @@ func (p Program) NewPackage(name, pkgPath string) Package {
 	p.NeedRuntime = false
 	// Don't need reset p.needPyInit here
 	// p.needPyInit = false
-	return &aPackage{mod, gbls, fns, stubs, pyobjs, pymods, p}
+	ret := &aPackage{
+		mod: mod, vars: gbls, fns: fns, stubs: stubs,
+		pyobjs: pyobjs, pymods: pymods, Prog: p}
+	ret.abi.Init(pkgPath)
+	return ret
+}
+
+// Tuple returns a tuple type.
+func (p Program) Tuple(typs ...Type) Type {
+	els := make([]*types.Var, len(typs))
+	for i, t := range typs {
+		els[i] = types.NewParam(token.NoPos, nil, "", t.raw.Type)
+	}
+	return p.rawType(types.NewTuple(els...))
+}
+
+// Eface returns the empty interface type.
+func (p Program) Eface() Type {
+	if p.efaceTy == nil {
+		p.efaceTy = p.rawType(tyAny)
+	}
+	return p.efaceTy
+}
+
+// AbiTypePtr returns *abi.Type.
+func (p Program) AbiTypePtr() Type {
+	if p.abiTyptr == nil {
+		p.abiTyptr = p.rawType(types.NewPointer(p.rtNamed("Type")))
+	}
+	return p.abiTyptr
+}
+
+// AbiTypePtrPtr returns **abi.Type.
+func (p Program) AbiTypePtrPtr() Type {
+	if p.abiTypptr == nil {
+		p.abiTypptr = p.Pointer(p.AbiTypePtr())
+	}
+	return p.abiTypptr
 }
 
 // PyObjectPtrPtr returns the **py.Object type.
@@ -388,6 +430,14 @@ func (p Program) Float64() Type {
 	return p.f64Ty
 }
 
+// Float32 returns float32 type.
+func (p Program) Float32() Type {
+	if p.f32Ty == nil {
+		p.f32Ty = p.rawType(types.Typ[types.Float32])
+	}
+	return p.f32Ty
+}
+
 // Byte returns byte type.
 func (p Program) Byte() Type {
 	if p.byteTy == nil {
@@ -440,6 +490,8 @@ func (p Program) Uint64() Type {
 // and unspecified other things too.
 type aPackage struct {
 	mod    llvm.Module
+	abi    abi.Builder
+	abiini []func(b unsafe.Pointer) // b Builder
 	vars   map[string]Global
 	fns    map[string]Function
 	stubs  map[string]Function
@@ -450,13 +502,6 @@ type aPackage struct {
 
 type Package = *aPackage
 
-/*
-// NewConst creates a new named constant.
-func (p Package) NewConst(name string, val constant.Value) NamedConst {
-	return &aNamedConst{}
-}
-*/
-
 func (p Package) rtFunc(fnName string) Expr {
 	fn := p.Prog.runtime().Scope().Lookup(fnName).(*types.Func)
 	name := FullName(fn.Pkg(), fnName)
@@ -509,6 +554,28 @@ func (p Package) String() string {
 	return p.mod.String()
 }
 
+// AfterInit is called after the package is initialized (init all packages that depends on).
+func (p Package) AfterInit(b Builder, ret BasicBlock) {
+	doAbiInit := len(p.abiini) > 0
+	doPyLoadModSyms := p.pyHasModSyms()
+	if doAbiInit || doPyLoadModSyms {
+		b.SetBlockEx(ret, afterInit, false)
+		if doAbiInit {
+			sigAbiInit := types.NewSignatureType(nil, nil, nil, nil, nil, false)
+			fn := p.NewFunc(p.abi.Pkg+".init$abi", sigAbiInit, InC)
+			fnb := fn.MakeBody(1)
+			for _, abiInit := range p.abiini {
+				abiInit(unsafe.Pointer(fnb))
+			}
+			fnb.Return()
+			b.Call(fn.Expr)
+		}
+		if doPyLoadModSyms {
+			p.pyLoadModSyms(b)
+		}
+	}
+}
+
 /*
 type CodeGenFileType = llvm.CodeGenFileType
 
@@ -676,7 +743,7 @@ func (p Program) tyGetAttrString() *types.Signature {
 func (p Package) PyInit() bool {
 	if fn := p.FuncOf("main"); fn != nil {
 		b := fn.NewBuilder()
-		b.SetBlockEx(fn.Block(0), AtStart).callPyInit()
+		b.SetBlockEx(fn.Block(0), AtStart, false).callPyInit()
 		b.Dispose()
 		return true
 	}
diff --git a/ssa/ssa_test.go b/ssa/ssa_test.go
index 103ee79e..3e23e756 100644
--- a/ssa/ssa_test.go
+++ b/ssa/ssa_test.go
@@ -52,7 +52,7 @@ func TestSetBlockEx(t *testing.T) {
 	}()
 	fn := &aFunction{}
 	b := &aBuilder{Func: fn}
-	b.SetBlockEx(&aBasicBlock{fn: fn}, -1)
+	b.SetBlockEx(&aBasicBlock{fn: fn}, -1, false)
 }
 
 func TestSetPython(t *testing.T) {
@@ -130,7 +130,7 @@ func TestAny(t *testing.T) {
 	prog.SetRuntime(func() *types.Package {
 		ret := types.NewPackage("runtime", "runtime")
 		scope := ret.Scope()
-		name := types.NewTypeName(0, ret, "Interface", nil)
+		name := types.NewTypeName(0, ret, "Eface", nil)
 		types.NewNamed(name, types.NewStruct(nil, nil), nil)
 		scope.Insert(name)
 		return ret
diff --git a/ssa/stmt_builder.go b/ssa/stmt_builder.go
index 2bbaf771..93c462a4 100644
--- a/ssa/stmt_builder.go
+++ b/ssa/stmt_builder.go
@@ -29,9 +29,10 @@ import (
 // -----------------------------------------------------------------------------
 
 type aBasicBlock struct {
-	impl llvm.BasicBlock
-	fn   Function
-	idx  int
+	first llvm.BasicBlock
+	last  llvm.BasicBlock
+	fn    Function
+	idx   int
 }
 
 // BasicBlock represents a basic block in a function.
@@ -51,6 +52,7 @@ func (p BasicBlock) Index() int {
 
 type aBuilder struct {
 	impl llvm.Builder
+	blk  BasicBlock
 	Func Function
 	Pkg  Package
 	Prog Program
@@ -64,12 +66,12 @@ func (b Builder) Dispose() {
 	b.impl.Dispose()
 }
 
-// SetBlock means SetBlockEx(blk, AtEnd).
+// SetBlock means SetBlockEx(blk, AtEnd, true).
 func (b Builder) SetBlock(blk BasicBlock) Builder {
 	if debugInstr {
 		log.Printf("Block _llgo_%v:\n", blk.idx)
 	}
-	b.SetBlockEx(blk, AtEnd)
+	b.SetBlockEx(blk, AtEnd, true)
 	return b
 }
 
@@ -82,20 +84,23 @@ const (
 )
 
 // SetBlockEx sets blk as current basic block and pos as its insert point.
-func (b Builder) SetBlockEx(blk BasicBlock, pos InsertPoint) Builder {
+func (b Builder) SetBlockEx(blk BasicBlock, pos InsertPoint, setBlk bool) Builder {
 	if b.Func != blk.fn {
 		panic("mismatched function")
 	}
 	switch pos {
 	case AtEnd:
-		b.impl.SetInsertPointAtEnd(blk.impl)
+		b.impl.SetInsertPointAtEnd(blk.last)
 	case AtStart:
-		b.impl.SetInsertPointBefore(blk.impl.FirstInstruction())
+		b.impl.SetInsertPointBefore(blk.first.FirstInstruction())
 	case afterInit:
-		b.impl.SetInsertPointBefore(instrAfterInit(blk.impl))
+		b.impl.SetInsertPointBefore(instrAfterInit(blk.first))
 	default:
 		panic("SetBlockEx: invalid pos")
 	}
+	if setBlk {
+		b.blk = blk
+	}
 	return b
 }
 
@@ -160,6 +165,22 @@ func (b Builder) Return(results ...Expr) {
 	}
 }
 
+// The Extract instruction yields component Index of Tuple.
+//
+// This is used to access the results of instructions with multiple
+// return values, such as Call, TypeAssert, Next, UnOp(ARROW) and
+// IndexExpr(Map).
+//
+// Example printed form:
+//
+//	t1 = extract t0 #1
+func (b Builder) Extract(x Expr, i int) (ret Expr) {
+	if debugInstr {
+		log.Printf("Extract %v, %d\n", x.impl, i)
+	}
+	return b.getField(x, i)
+}
+
 // Jump emits a jump instruction.
 func (b Builder) Jump(jmpb BasicBlock) {
 	if b.Func != jmpb.fn {
@@ -168,7 +189,7 @@ func (b Builder) Jump(jmpb BasicBlock) {
 	if debugInstr {
 		log.Printf("Jump _llgo_%v\n", jmpb.idx)
 	}
-	b.impl.CreateBr(jmpb.impl)
+	b.impl.CreateBr(jmpb.first)
 }
 
 // If emits an if instruction.
@@ -179,7 +200,7 @@ func (b Builder) If(cond Expr, thenb, elseb BasicBlock) {
 	if debugInstr {
 		log.Printf("If %v, _llgo_%v, _llgo_%v\n", cond.impl, thenb.idx, elseb.idx)
 	}
-	b.impl.CreateCondBr(cond.impl, thenb.impl, elseb.impl)
+	b.impl.CreateCondBr(cond.impl, thenb.first, elseb.first)
 }
 
 // The MapUpdate instruction updates the association of Map[Key] to
diff --git a/ssa/type.go b/ssa/type.go
index b7307c39..d8ba01a7 100644
--- a/ssa/type.go
+++ b/ssa/type.go
@@ -49,7 +49,9 @@ const (
 	vkSlice
 	vkArray
 	vkMap
-	vkInterface
+	vkEface
+	vkIface
+	vkStruct
 	vkPhisExpr = -1
 )
 
@@ -73,7 +75,7 @@ func indexType(t types.Type) types.Type {
 // -----------------------------------------------------------------------------
 
 type rawType struct {
-	types.Type
+	Type types.Type
 }
 
 type aType struct {
@@ -99,6 +101,22 @@ func (p Program) SizeOf(typ Type, n ...int64) uint64 {
 	return size
 }
 
+// OffsetOf returns the offset of a field in a struct.
+func (p Program) OffsetOf(typ Type, i int) uint64 {
+	return p.td.ElementOffset(typ.ll, i)
+}
+
+// SizeOf returns the size of a type.
+func SizeOf(prog Program, t Type, n ...int64) Expr {
+	size := prog.SizeOf(t, n...)
+	return prog.IntVal(size, prog.Uintptr())
+}
+
+func OffsetOf(prog Program, t Type, i int) Expr {
+	offset := prog.OffsetOf(t, i)
+	return prog.IntVal(offset, prog.Uintptr())
+}
+
 func (p Program) PointerSize() int {
 	return p.td.PointerSize()
 }
@@ -113,7 +131,6 @@ func (p Program) Pointer(typ Type) Type {
 
 func (p Program) Elem(typ Type) Type {
 	elem := typ.raw.Type.(interface {
-		types.Type
 		Elem() types.Type
 	}).Elem()
 	return p.rawType(elem)
@@ -124,9 +141,14 @@ func (p Program) Index(typ Type) Type {
 }
 
 func (p Program) Field(typ Type, i int) Type {
-	tunder := typ.raw.Type.Underlying()
-	tfld := tunder.(*types.Struct).Field(i).Type()
-	return p.rawType(tfld)
+	var fld *types.Var
+	switch t := typ.raw.Type.(type) {
+	case *types.Tuple:
+		fld = t.At(i)
+	default:
+		fld = t.Underlying().(*types.Struct).Field(i)
+	}
+	return p.rawType(fld.Type())
 }
 
 func (p Program) rawType(raw types.Type) Type {
@@ -201,9 +223,11 @@ func (p Program) tyInt64() llvm.Type {
 	return p.int64Type
 }
 
+/*
 func (p Program) toTuple(typ *types.Tuple) Type {
 	return &aType{p.toLLVMTuple(typ), rawType{typ}, vkTuple}
 }
+*/
 
 func (p Program) toType(raw types.Type) Type {
 	typ := rawType{raw}
@@ -247,7 +271,9 @@ func (p Program) toType(raw types.Type) Type {
 		elem := p.rawType(t.Elem())
 		return &aType{llvm.PointerType(elem.ll, 0), typ, vkPtr}
 	case *types.Interface:
-		return &aType{p.rtIface(), typ, vkInterface}
+		if t.Empty() {
+			return &aType{p.rtEface(), typ, vkEface}
+		}
 	case *types.Slice:
 		return &aType{p.rtSlice(), typ, vkSlice}
 	case *types.Map:
@@ -259,12 +285,14 @@ func (p Program) toType(raw types.Type) Type {
 		return p.toNamed(t)
 	case *types.Signature: // represents a C function pointer in raw type
 		return &aType{p.toLLVMFuncPtr(t), typ, vkFuncPtr}
+	case *types.Tuple:
+		return &aType{p.toLLVMTuple(t), typ, vkTuple}
 	case *types.Array:
 		elem := p.rawType(t.Elem())
 		return &aType{llvm.ArrayType(elem.ll, int(t.Len())), typ, vkArray}
 	case *types.Chan:
 	}
-	panic(fmt.Sprintf("toLLVMType: todo - %T\n", typ))
+	panic(fmt.Sprintf("toLLVMType: todo - %T\n", raw))
 }
 
 func (p Program) toLLVMNamedStruct(name string, raw *types.Struct) llvm.Type {
@@ -283,6 +311,8 @@ func (p Program) toLLVMStruct(raw *types.Struct) (ret llvm.Type, kind valueKind)
 	ret = p.ctx.StructType(fields, false)
 	if isClosure(raw) {
 		kind = vkClosure
+	} else {
+		kind = vkStruct
 	}
 	return
 }
@@ -364,7 +394,7 @@ func (p Program) toNamed(raw *types.Named) Type {
 	switch t := raw.Underlying().(type) {
 	case *types.Struct:
 		name := NameOf(raw)
-		return &aType{p.toLLVMNamedStruct(name, t), rawType{raw}, vkInvalid}
+		return &aType{p.toLLVMNamedStruct(name, t), rawType{raw}, vkStruct}
 	default:
 		return p.rawType(t)
 	}